
Class _ 
Book.... 



coPYiiicm i 



- 



£§e'5°w>(Koc60: 

©ana. 



ON THE FOUR ROCKS 



THE NEW HAVEN REGION, 



EAST ROCK, WEST ROCK, PINE ROCK AND MILL ROCK, 



IN ILLUSTRATION OF THE FEATURES 



NON-VOLCANIC IGNEOUS EJECTIONS. 



WITH A GUIDE TO WALKS AND DRIVES ABOUT NEW HAVEN. 



BY S 

JAMES D. DANA. 



„ G n G> cV ' 



■ 
NEW HAVEN: 

TUTTLE, MOREHOUSE & TAYLOR, PRINTERS. 
1891. 



Copyright, 1891 

by 
James D. Dana. 






PREFATORY EXPLANATIONS 

For New Haven readers and others not versed in Geology. 



Of the four grander divisions of geological time, the Archaean 
is probably represented by the crystalline rocks of the eastern 
border of the New Haven region ; the early Paleozoic, by those 
of the western border ; the Mesozoic, unquestionably, by the Red 
Sandstone which is the substratum of the whole region ; and the 
Cenozoic, by the superficial river-made deposits of the plain. 
Accordingly, the Cenozoic beds rest on the Mesozoic Red Sand- 
stone ; and the Mesozoic, on crystalline rocks of either Paleozoic 
or Archaean age. The three periods of Mesozoic time are the 
Triassic, the Jurassic and the Cretaceous or Chalk period. The 
Red sandstone, which outcrops about all the ridges and is well 
exhibited at the East Haven quarries, was made during the later 
part of the Triassic period and part of the Jurassic, and hence it 
is called the Jura-Trias sandstone. 

New Haven bay is both topographically and geologically the 
termination of the Connecticut valley. In the period of the Jura- 
Trias, an estuary, ten to thirty miles wide, extended along the val- 
ley to northern Massachusetts ; and in this estuary the sandstone 
was formed, nearly as sand-beds are now formed in a Delaware 
bay. The sands were made from the decay of granite, gneiss, 
mica schist, and other related rocks on either side of the estuary; 
and they were carried into the estuary by the streams of the land. 
The waters of the estuary are known to have been either fresh or 
brackish, by the absence from the fossils of remains of marine 
life. The stone of Portland, Conn., so much used for fine build- 
ings, and that of Longmeadow, Mass., also of great architectural 
value, are of this formation, as well as the excellent building 
stone of East Haven. 

The population of New England at this period the reader will 
find described in geological treatises. Large portions of skele- 
tons of Connecticut reptiles well preserved, have recently come 



iv Prefatory Explanations. 

into the possession of Professor Marsh, from the quarries near 
Hartford. 

This sandstone is almost every where in an upturned condition 
as a result of subterranean movements. The beds, with few ex- 
ceptions, have consequently an eastward pitch of 15° to 25°. 
After the upturning had been to a large extent completed in the 
New Haven region, the eruptions of trap took place from great 
fissures opened through the sandstone and the underlying rocks 
of the earth's crust. The lava which then came up and filled the 
fissures, and in many places outflowed, is the rock we now call 
trap. Eruptions also took place through the whole length of the 
Connecticut valley, probably simultaneously with those of New 
Haven. The trap of the Hanging Hills of Meriden, and of the 
line of heights reaching to Mt. Tom and Mt. Holyoke in Massa- 
chusetts, was ejected in this epoch of New England history. 

Trap is essentially identical in composition with the lavas of 
the Sandwich Islands and with the basalt of the Giant's Causeway. 
It is the most fusible of the common igneous rocks, as illustrated 
in the volcanoes of Hawaii. It consists of the minerals pyroxene, 
a silicate of iron, lime and magnesia, and the fusible feldspar 
called labradorite, along with some magnetite. The iron-rust 
color which so frequently covers the surfaces of the trap proceeds 
from the oxidation of the iron in the pyroxene, and the ordinary 
decay of trap is largely a consequence of the same process. 
Another mineral of like constituents with pyroxene, called chryso- 
lite or olivine, occurs in true basalt, and when present it aids in 
the decay. It has been found sparingly in the trap of Orange, 
N. J. 

The term laccolith applied beyond to the outflows of trap is 
from the Greek for lake and sto?ie, and alludes, as explained by 
Professor Gilbert, to the fact that the outflow is a subterranean 
widening out of the lava-stream ascending a fissure, somewhat as 
a lake is a widened stream of water. 

The sandstone of the Jura-Trias continued to be formed in 
some parts of the estuary after eruptions of trap had taken place. 
Evidence of this has been found in the occurrence of stones 
of trap in the sandstone of Massachusetts, as first made known 
by Prof. B. K. Emerson of Amherst. Similar evidence has also 
been observed in East Haven by Prof. W. M. Davis ; and more 
recently by Dr. E. O. Hovey, in the beds east of Saltonstall Lake. 



Prefatory Explanations. v 

No rocks or relics of the Cretaceous period have been observed 
in Connecticut. The first of the two eras of Cenozoic time, the 
Tertiary, is also, as far as known, unrepresented. But the second, 
the Quaternary, has left its records in the bowlders, scattered 
stones, and river deposits of all New England. The "Judges' 
Cave " is one of the bowlders, though now in pieces. The mass, 
though weighing probably 1000 tons, was transported by the ice of 
the Glacial era from some point between Mt. Tom and Meriden. 
Its companions in travel, many of them between 100 and 500 
tons in weight, are scattered all along the western border of the 
New Haven region and but few elsewhere. The largest, weigh- 
ing full 1200 tons, lies just below the top of the Woodbridge 
heights, directly west of the Judges' Cave and hardly a mile and 
a half distant. 

The thickness of the slowly flowing glacier over the New Haven 
region was at least 1000 feet \ for in the southwestern corner of 
Massachusetts, only 60 miles distant, it was not less than 2500 
feet, as proved by the scratches it left on the high summit of the 
region, Mt. Washington. Moreover, large bowlders of trap and 
other rocks were carried by the ice from Connecticut to Long 
Island ; and the slope of the upper surface would hardly have 
been sufficient for this flow of 30 to 40 miles with less than 1000 
feet of height in southern Connecticut. 

The scratches made about New Haven and elsewhere in the 
Connecticut valley by the stones in the bottom of the glacier, 
and also the travelled bowlders, prove that the movement here 
was in the direction of the valley, or about S. 10° W. to S. 15° W. 
But over high western Connecticut the same evidence makes the 
movement S. 30° E. to S. 40° E. The latter was the prevailing 
course of the glacier also over the Connecticut valley, except for the 
lower part of the ice lying within the valley ; for a valley is like 
a groove in confining and giving direction to the flowing material 
within it, whatever the direction above the level of the groove. 
Consequently, bowlders of granite, gneiss and other rocks from 
the higher parts of western Connecticut might have passed over 
the Connecticut valley if they could keep in the upper current. 
But if large, they would have gradually sunk in the glacier, be- 
cause of their weight and the many crevasses, until within the 
southward-flowing bottom ice, and thus be made to join the val- 



vi Prefatory Explanations. 

ley bowlders for the rest of their journey. The New Haven re- 
gion thus got many a bowlder of granite, gneiss and quartzyte 
from the west, the "hard-heads" of quartzyte probably coming 
from Canaan, the gneiss and granite from Seymour and beyond. 
Next came the Champlain period or that of the melting of the 
glacier. The melting of a winter's ice makes now great floods 
in the spring ; then it was the melting of the ice of many cen- 
turies of winters. The floods filling the valleys transported the 
sand and gravel which the ice let loose and made the terraces 
along the rivers. The waters of West river, Mill river and the 
Quinnipiac in this way built up and levelled off the New Haven 
plain. The plain owes its width to their combination in one broad 
flood before reaching the New Haven Bay : first, the union, south 
of West Rock, of the waters of West river and Mill river, and, 
finally, that of all together, south of East Rock. These facts re- 
specting the plain are illustrated on the first two of the accom- 
panying maps. 



THE FOUR "ROCKS 



NEW HAVEN REGION/ 



The observations on the igneous ejections of the New Haven 
region here recorded and discussed were mostly completed 
during the years 1879 and 1880, shortly after the publication 
(in 1877) of a detailed topographical map of the region by the 
U. S. Coast and Geodetic Survey, made under the special 
direction of R. M. Bache. As this map is on the large scale 
of T -jnta"o> or aD0ll t ®i inches to the mile, and has 20-foot 
contour lines, it afforded a very convenient basis for the record 
of geological facts. 

A reduction of a portion of this map to a scale of two miles 
to the inch, is presented on Plate Ilf and a general map of the 
whole New Haven Region, to Mt. Carmel on the north and 
Saltonstall Ridge and Lake on the west, on Plate I. Except- 

* This chapter, on the Eruptive epoch in the geological history of the New Haven 
region, is republished from the Am. Journal of Science, Vol. XLII, August, 1891. 

f This map is a portion of Plate II in the writer's paper on the " Phenomena of 
the Glacial and Champlain Periods about the mouth of the Counecticut Valley, or 
the New Haven Region " published in the American Journal of Science, xxvii, 113, 
Feb. 1884). The limit of the New Haven plain is marked by a dotted line at the 
base of the hills, and the contour-lines over it are omitted, the heights instead being 
given after a special survey. The small nearly circular depressions marked on 
the map represent " Kettle-holes." The New Haven plain was of river-flood ori- 
gin and it is presented on the map with the outlines and height unaltered by the 
gradings for road-making, and by the making of mill-dams; and hence the map 
is a map of the region of New Haven before 1640, as stated in its title. 



2 The Four Rocks of the New Haven Region. 

ing the hills in the southwestern corner of the map making 
Plate II, its whole area, even that of the New Haven plain, is 
underlaid by the Jura-Trias Red-sandstone formation. (The 
excepted hills are part of the border of metamorphic schists that 
bounds the Jura-Trias region on the west.) The map shows 
the positions of the four trap ridges — more strictly trap-and- 
sandstone ridges — West Rock, Pine Rock, Mill Rock and East 
Rock, and gives their heights above mean tide. These rampart- 
like elevations are now two to three miles from New Haven 
Bay ; but they bear evidence of having been for a time the 
headlands of a much larger bay. 

The ridges are part of the Jura-Trias Mountain-range of the 
Connecticut Valley. (1) East Rock and West Rock are like 
the other north-and-south ridges of the range in their form, 
structure and direction, and West Rock ridge after a course of 
seventeen miles, dies out just where the higher trap ridges of 
the Mt. Tom line commence, showing an interlocking with the 
rest of the system. (2) They consist of Jura-Trias sandstone 
with an intercalated sheet of trap (as the igneous rock is pop- 
ularly called). (3) The sheet of trap in the ridges has a rising 
inclination westward, or a dip eastward, like the associated 
beds of sandstone, the liquid rock having been extruded from 
a fissure or fissures situated somewhere to the eastward. (4) 
As a consequence of these common features, denudation by 
water and ice has given to the New Haven ridges the features 
typical of the range,* namely, a steep western front, consisting 
of sandstone below and the harder trap above, a top of bare 
trap, and eastern slopes of sandstone, that is of the overlying 
sandstone. 

From such common features the inference as to a common 
method of origin is natural. Still, as Professor Davis claims, 
it needs also other support for acceptance. 

We note also (4) that these Rocks are situated at the south- 
ern extremity of the Jura-Trias Mountain-range ; for the Con- 

•• In the writer's paper on the Geology of the New Haven region of 1869, 
(Transactions of the Connecticut Academy ol Sciences, ii, 4, 1870), he observes that 
" the sandstone mass with its intersecting dikes of trap constituted the block out of 
which the future New Haven region was to be carved by various denuding agencies." 



The Four Rocks of the New Haven Region. 3 

necticut Valley and its Jura-Trias beds do not extend over 
Long Island. Instead of this, Long Island pertains to an east- 
and-west system of mountain-structure. Whether nearness in 
position to this east-and-west range has occasioned any of the 
features of the Rocks is an interesting question for con- 
sideration. 

1. Summary of the principal pacts and conclusions. 

The facts. — The facts relate to the sandstone of the New 
Haven region as well as the trap ; for the sandstone was broken 
through to give exit to the liquid trap, and it broke as such a 
sandstone would break. 

(1) The sandstone, as the rock is comprehensively called, 
varies from fine-grained to coarse, and beyond this,, to a fine 
and coarse conglomerate, even cobble-stone-gravel conglomer- 
ate. When fine-grained and shaly it is not a firm laminated 
rock, but divides or crumbles readily to thin chips. The more 
massive kinds are usually traversed with fractures; and none 
has much firmness except where consolidated by heat from the 
trap-ejections, or the hot vapors produced thereby. Conse- 
quently, fissures made though the formation should have great 
irregularities, from irregular fracturing and the tumbling into 
them of masses of sandstone and large sections of their walls. 

(2) The thickness of the sandstone intersected by the fissures 
over the center of the New Haven region was at least 3000 
feet, as proved by borings at a point half way between the bay 
and the west end of Mill Rock. Along the West Rock line 
the depth was probably less, as this ridge is within a mile 
and a half of the western metamorphic limit of the Connecti- 
cut Yalley of Triassic time. Beneath the sandstone the fissures 
came up through underlying crystalline rocks, in which they 
would probably have great regularity in course, width and con- 
tinuity. 

(3) When the heat from the trap, or the hot vapors gener- 
ated by it, consolidated the sandstone, it generally made hard, 
durable rock of the coarser kind, but left the finer beds, 
alternating with the coarse, fragile and chip-making ; and this 



4 The Four Rocks of the New Haven Region. 

was so, apparently, because hot vapor penetrates most easily 
the coarser beds for the cementing work. The heat, through 
the penetrating vapors, generally discharged more or less com- 
pletely the color of the beds it consolidated, producing an ash- 
gray and brownish shade ; made in them steam tubes with 
blanched walls ; produced blotches of impure chlorite, or 
epidote, and crystallizations of hematite and epidote, and less 
commonly garnet. But the finer beds that alternate with the 
coarse commonly retain, except perhaps for a few inches, their 
red color, and even have it deepened to a dark purplish red — 
as if by the reduction of some of the red coloring matter 
(oxide of iron) to magnetite. Moreover, the sandstone often 
loses all the old bedding. These varying effects from the heat 
have added much to the original irregularities of the beds. 

(1) Of the four Rocks, East and West belong to the prevail- 
ing north-and- south system, as already stated ; the other two, 
Pine Rock and Mill Rock, to a transverse system. 

(2) In East Rock and West Rock the sheet of trap made 
by ontiiow from the opened fissure or fissures has a length 
westward of 100 to 500 yards. 

(3) The supply fissure, or its filling, the dike, descends be- 
neath the eastern slope with a large eastward pitch : the angle 
of pitch in the case of East Rock being about 50°. 

(4) In Pine Rock and Mill Rock, the trap is in dikes, there 
being no evidence of any outflow. Yet these dikes have in 
some of the outlets the great breadth of 150 to 300 or more 
feet. 

(5) The pitch of these dikes is to the northward ; and its 
angle 18° to 40° — both characters of unusual interest. 

(6) Although neither East Rock, Mill Rock nor Pine Rock 
has a length exceeding a mile and a half, each has three or four 
distinct outlets of trap, separated by intervening sandstone ; 
moreover, there is wide diversity between the Rocks in the 
form and arrangement of these areas of extruded trap, as the 
map illustrates. 

(7) The trap of the several ridges, according to examinations 
by E. S. Dana, is true doleryte, free, or nearly so, from chlorite 



The Four Rocks of the New Haven Region. 5 

and other evidences of interior alteration, and not at all 
vesicular. 

(8) Columnar fractures give the rock a rudely columnar 
structure, in which the half-defined columns are four to eight feet 
in diameter. In the west fronts of the north and south ridges 
the rude columns have usually an inclination nearly at right 
angles to the mean dip of the associated sandstone — accord- 
ing thus with the usual rule : perpendicular to the cooling sur- 
faces. But among the columnar fractures, whatever the incli- 
nation of the columns, that plane of fracture or joint which is 
transverse to the sides of the dike or trap-mass and nearly ver- 
tical is the most strongly developed, and consequently the 
trap often cleaves into nearly vertical plates or laminae of 
great extent, much like a laminated rock. There usually is 
also a second easy cleavage-direction, nearly at right angles to 
the former so that rectangular columns sometimes come out 
with great prominence. 

(9) The outflows of trap have a floor either of an inclined 
layer of the sandstone or of edges of the upturned layers. 

The principal conclusions. — (1) The igneous eruptions of 
the New Haven region took place after the sandstone had been 
upturned ; that is, after the evolution of the Connecticut- valley 
mountain-range in this part of the valley had made great 
progress. 

(2) None of them were volcanic eruptions, for there was no 
center of action, no pericentric discharge of volcanic materials. 

(3) In the outflows from the fissures (those of East and 
West Rock) the liquid trap did not escape into the open air 
and spread over the surface, but entered between layers of the 
sandstone. 

(4) Moreover the flow was not by gravity into spaces that 
had been previously made, but a forced flow that opened 
spaces or chambers for its occupation, the liquid rock thus 
lifting the overlying sandstone as long as the discharge was 
continued. By such means the sheets of liquid trap attained, 
in some cases, a thickness of 300 or more feet. This forcible 



6 The Four Hock* of the New Haven Region. 

opening and filling of a chamber in the sandstone by the up- 
thrust lavas, is a laccolithic process, it according with that of the 
typical laccoliths ably studied out and described by Gilbert.* 

(5) The intrusion of the flowing rock between the sandstone 
layers took place at comparatively shallow depths, where the 
pressure of the rock was not too great to prevent it. 

(6) It was favored, in each case, by the fact that the 
oblique fissure supplying the lava was inclined in the same 
direction with the layers of the uplifted sandstone — both in- 
clining westward, the dip being eastward. 

(7) The termination of a fissure in several outlets, exempli- 
fied in three of the Rocks, was largely due to the great incli- 
nation and depth of the fissures opened through the weak 
upturned and faulted sandstone, and thence to great downfalls 
of the hanging wall. The same cause led to irregularities in 
the width and forms of dikes, and influenced the outlines and 
surface-features of outflows. 

(8) The course and dip of supply-fissures was not deter- 
mined by the foliation or bedding of the schists underneath 
the sandstone. 

2. Special facts from the several Hocks illustrating the 
above conclusions. 

The ridges, Pine Rock and Mill Rock, containing simple 
dikes are first considered, and then East Rock and West Rock, 
which include dikes and outflows from them.f 

1. PINE ROCK. 

The general form of Pine Rock is shown on Plate II, and 
still better on the following larger map.;}: It is only three- 

* Geulogy of the Henry Mountains by G. K. Gilbert, 4to, 1877. 

\ In justice to Percival, the author of the Report on the Geology of Connecti- 
cut of 1842, it should be here stated that there is scarcely an outlet or area of 
trap mentioned beyond which is not recorded on his map or described in his 
Report. 

\ The 20-foot contour lines on this map, and also those on that of Mill Rock 
pn page 11, are copied from the Bache Coast Survey map. 



Pine Rock. 7 

fourths of a mile long and trends N. 67° E., or east-northeast. 
This small ridge has three, perhaps four, independent outlets 
of trap, A, BB', CC and D. The first, at the west end, is a 
small dike 15 to 20 feet wide, trending north 20° west, and 
traceable for 220 feet. It dips eastward 25°, and thus proves 




Map of Pine Rock. Heights reckoned from high-tide level, 
with dotted outline. 



Areas of trap 



that it is not an outlier of West Rock, but part of the Pine 
Rock group. The other three are, more evidently, outlets from 
one great fissure. The width of the larger mass, CC, is about 




300 feet ; and it is therefore one of the widest of dikes. The 
dip of the dike is 50° to 55° northwestward. This inclined 



s 



The Four Rocks of the New Haven Region. 



position (35° to 40° from a vertical) is given the dike in fig. 2, in 
which DIKE represents a section of it between its sandstone 
walls before denudation, and d i K E, the same through the 
highest point of the Rock as it now is — or was before recent 
quarrying. The cross-lining gives the direction of the columnar 
fractures. The other figure, fig. 3, is a section through v on 
the map, where the removal of the sandstone of the southern 
wall (v, in the section) has left a depression called the Cave. 
(The sandstone of these sections is now concealed by the debris, 
and outside of this by the Terrace formation.) 

The southern wall of the dike is the roof of the cave ; the 
rock has the fine texture and fissured surface usual where it 
cooled in contact with the sandstone. Just above the cave, 




Inclined columns of Pine Rock, above the "Cave." 



where the exterior is removed, the surface is made up of the 
ends of rude columns. A profile view of these inclined 
columns from a point just south is shown in fig. 4.* 

At w, (see the preceding map) the north wall of the inclined 

* From a photograph by G. N. Lawson, of the class at Yale of 1890 ; taken in 
December, 181)0. 



Pine Rock. 9 

dike is uncovered for a height of 50 feet, the sandstone having 
been carried off by the glacier.* 

At the eastern extremity of Pine Pock (near C), the trap 
of the north wall may be seen in contact with hard-baked 
sandstone. In the large quarry just south, the rock exhibits 
finely the transverse lamination crossing the dike — referred to 
on page 4. The laminae incline 10° to 15° to the eastward, 
the dip being 80 to 85° to the westward. The surfaces of the 
plates are usually yellowish-brown with limonite for scores of 
feet from the summit, owing to the waters that penetrate from 
the surface downward and oxydize the iron of the rock ; but 
in the transverse joints or cracks, which are less accessible to 
the waters, there is usually a coating of stilbite and sometimes 
of other zeolites, as chabazite, analcite, heulandite.f The 
dike has a few transverse courses of fracture containing prehnite 
and occasionally apophyllite, but no longitudinal have been 
observed. 

A sandstone ridge connects A and BB', in which the rock is 
hard, and has the strike N. 40°-45° E., and the dip 45° S., 
becoming N. 30° E. and 30° to 35° in dip more to the west. 
It is mostly a coarse sandstone ; but some layers contain stones 
4 to 5 inches in diameter. 

Origin of the Features of the Rock. 

The existence of so many outlets of trap in the small space, 
and the irregular forms of the areas are unusual facts. BB' is 
short, broad and blunt, shield-shaped ; and CC', is duck-like in 
shape, the irregular bosses at the northwest end (EE') making 
the neck and head. These bosses are not in the line of the 
dike, and must be due to a local catastrophe. In view of the 
great inclination of the fissure, and its depth of 2000 to 3000 

* The shaping of the northern slopes of the Pine Rock ridge is a part of the 
same work of the ice ; and the trend of the mass, like that of Sachem's Ridge, 
(Plate II), indicates the direction of movement of the glacier. The same is true 
for the northern slopes of Whitney Peak and Indian Head. 

f The surface of the crust of zeolites is frequently tinged with the red iron 
oxide— which is a probable indication of heat as higli at least as 200° F. dur- 
ing the formation of the minerals. 



10 The Four Rocks of the New Haven Region. 

feet in the weak sandstone, a caving in of some part of its 
northern or hanging wall would be of extreme probability. 
Such a catastrophe would account for the stoppage of the out- 
flow and the separation thus of BB' and CC ; and snch a 
stoppage of the up-thrust lavas would explain their escape by 
one or more extemporized outlets, and for the actual position 
of the apertures on the north side of the fissure ; and thereby 
for the making of the bosses. The obstructed lavas of the 
fissure may also have found exit in the western dike, A. 

The trap-mass D is possibly a result of a second smaller 
catastrophe of like character; but its separation from CC, may 
be a result of erosion. 

Another consequence of the great inclination of the fissure is 
the exposure of the dike of heavy trap to degradation through 
the removal of the supporting sandstone on the south side. 
Such undermining has produced the steepness of the southern 
front. And sea-shore waves or breakers were probably the 
chief agent — the shores being those of the broad center, or a 
central arm, of the New Haven Bay. 

2. MILL ROCK AND THE WHITNEY RIDGE. 

Mill Rock is one mile distant from the east end of Pine 
Rock. Its length to Whitneyville or Mill River, is four-fifths 
of a mile. This small area, as is seen on Plate II, and better in 
the following larger map, has four independent outlets of trap — 
the western, A A', the eastern, BB' ; north of the gap between 
these, a short narrow dike C, and farther north, the isolated 
area, D. The width of the first, AA', (as measured at its west 
end) is 200 feet; of the second, 140 or 150 feet; of the third, 
1 to 10 feet ; of the fourth, 50 feet, the length being 150. 
The mass BB' continues to Mill River where the surface of the 
country declines to tide level. But the trap does not stop 
here ; it crosses the river and extends on eastward, with an in- 
creased width, 180 feet, to the summit of Whitney Peak. 
The Whitney Peak dike belongs therefore to the Mill Rock 
region, although topographically part of the East Rock area. 
The trend of the Whitney Peak portion is S. 68° E.; of AA', 



Mill Rock. 



11 



S. 78° E. The mean course for the whole series to the summit 
of Whitney Peak is about S. 72° E. 





Map of Mill Rock, excepting its eastern extremity. Trap areas with dotted 

outlines. 

The dip or pitch of the main dike is about 72° to the north- 
ward, or 18° from the vertical. This inclination and the course 
of the columnar fractures are 
well exhibited at the west end 
of the dike, A, and are repre- 
sented in figure 6. 

Besides the columnar frac- 
tures at right angles to the 
walls, there are also longitudi- 
nal fractures in interrupted lines, parallel to the walls. Two 
are seen at the west end of the Rock and are indicated in the 
above figure. They are now mineral veins. The more south- 
ern one, a, contains chiefly prehnite, with traces of copper ore, 
and the trap along its course is solid or little altered. The 
other is situated about half way between the sides. It con- 
tains abundantly the very hydrous mineral laumontite and the 
trap along it is decomposed ; it contains also impure chlorite, 



Section of Mill Rock, west end. 



12 The Four Rocks of the New Haven Region. 

and is fragile for a breadth of six to ten inches. A similar 
laumontite vein, but nearer the north wall of tke dike, is seen 
at Whitnevville, and also in the trap of Whitney Peak. 

The junction of the Whitney Peak part of the dike with 
BB' takes place in the bed of the stream at Whitnevville, and 
is not now exposed to view owing to the dam and the build- 
ings below it.* 

The level of the trap beneath the dam is but a few feet 
above and below tide level. The height of the Whitney 
Peak dike increases eastward ; first by a sudden rise of 100 
feet, and then more gradually in the last 500 yards to 280 
feet. Whitney Peak has a bold front to the eastward with 
sandstone at its base showing a sudden stoppage of the fissure 
in that direction ; and at the same place it widens southward — 
not by overflow, as the precipitous eastward front and the 
depth of the trap shows, but through the opening of a trans- 
verse fissure. The Rock has a steep wall 70 to 80 feet high, on 
the north side of the summit for nearly 100 yards; but this 
is due to the removal of the sandstone by glacier action, expos- 
ing the north wall of the trap dike. 

The narrow dike C is about 110 feet long. It is situated in 
the face of a bluff of sandstone; and from the evidences of 
heat in the hardness of the rock, its mottled and light gray 
color in places, its steam tubes, and epidote, it is plain that the 
ejection determined the resisting power of the sandstone 
against denuding agencies. The following figures represent 
two cross sections from the western half, and a map of the last 
40 feet of the eastern half. At 65 feet the outflow is divided, 
a narrow stream of trap (fig. 9), coming out above a layer of 
the sandstone 5 to 6 feet thick, the main part of the dike appear- 

* To the fact of this continuation I have recent testimony from Mr. Eli Whit- 
ney, who has superintended the constructions made there during the past forty 
years. Besides mentioning that the dam was built along the junction of the trap 
and sandstone, ho says that below the dam for some distance, there is trap rock 
only, no sandstone outcropping there to his knowledge. 

The gun factory at Whitnevville was established there by his father, the in- 
ventor of the cotton-gin, in 179S. for the manufacture of muskets for the United 
States Army. 



Mill Bock. 13 

ing below. This envelope of sandstone by trap continues for 30 
feet, when the two parts come together again. The depth 
at which the side stream goes off from the main dike is not 
known. The inclination of the dike is mostly 25° to 28° (fig. 7) 
from a vertical, but at 45 feet from the west end it becomes 40° 
(tig. 8), and 10 feet beyond this, 30°. 

7. 8. 9. 




The sandstone of the Mill Rock region is of all degrees of 
coarseness up to cobble-stone conglomerate ; and no distinction 
is observable between that of the west and east ends. 

Origin of the Mill Rock features. 

The subdivision of the trap into its four masses may be ex- 
plained in the same way as that in the Pine Rock area. A 
downfall of the northern sandstone wall of the fissure, the 
hanging wall, would account for the separation of AA' and 
BB'. Further, the obstruction thus occasioned to the great as- 
cending stream — its width 150 to 200 feet — would have forced 
open passages to the surface for the discharge of the liquid 
trap, and thus may have been produced the small dike C, 
situated near the fissure wall, and the remoter mass D. The 
irregularities of the little dike C, and the situation of both C 
and D to the north of the line of the dike, accord with this 
idea of a downfall of a part of the northern, wall. The 
liability to such a catastrophe in a wall made of the rude sand- 
stone 3000 feet or more high, and having a large inclination, 
was augmented in both Pine Rock and Mill Rock by the tilted 
position and faulted state of the sandstone. The beds had 
already received their eastward dip of 15° to 25°, and 
breaks and faults innumerable that had been made in the 



1 -f The Four Rocks of the New Haven Region. 

adjustment to the new tilted position ; it was therefore a 
tottlish structure overhanging a profound aby§s. The fact 
here introduced that the eastward pitch of the sandstone was 
given it before the ejection of the trap is sustained by facts 
reported beyond. But an argument for it is afforded here : 
for if this eastward pitch were of subsequent origin, then the 
Whitney Peak end of the system should be the lowest. In- 
stead of this it is greatly the highest ; the ridge slopes west- 
ward. 

It is possible that the fissures of AA' and BB' were, from 
the first, independent fissures to a considerable depth ; for they 
are not in precisely the same line. If this were so, the above 
explanation, while in the chief points right, would require 
some modification. 

As in Pine Rock, so with Mill Rock but to a less degree, 
the northward pitch of the dike made it easy of degradation 
by sea-shore action. Through such means, beyond doubt, the 
part of it extending from Mill River westward for 300 yards, 
was reduced to a width above ground of 40 to 50 feet. This 
narrowing commences just west of the Pumping House of the 
City Water Works (p, fig. 5), and continues without inter- 
ruption to the river. It is part of the evidence of a greater 
New Haven Bay at some former time. 

Why the range falls gradually to so low a level at Whitney - 
ville, appears to be explained only on the view that less trap 
here came to the surface. I have elsewhere shown that it 
cannot be due to glacial removal. Neither is it probable that 
fluvial or marine waters have produced it. We have to attri- 
bute it to some condition existing or produced in the supply - 
fissures of eastern Mill Rock and Whitney Peak, at the time 
they were opened. 

Besides the dikes of Pine Rock and Mill Rock, there is another 
transverse dike of special interest which intersects the West Rock 
ridge just below the margin of Wintergreen Lake, or about one 
and a quarter miles north of the southern termination of the ridge 
and four miles from New Haven Bay. It descends the eastern 
slope of West Rock in an interrupted ridge, forms part of the 



East Rook. 15 

southern bank of Wintergreen Lake, sinks to the level of the 
West Rock surface at the summit, but stands out like a buttress 
along the steep west front of the Rock. From the last feature 
I have called it for the past twenty years, the "Buttress dike." 
It extends south-westward through the metamorphic region 
of the towns of Woodbridge and Orange to the mouth of the 
Housatonic — as long since mapped and described by Percival. 
This dike has a pitch northward, amounting to 25° from a vertical 
in the part of it intersecting West Rock, but in that through 
the metamorphic rocks it is nearly vertical.* The strike of 
the inclined columns in the buttress portion is S. 30-32° E. It 
is an example of a dike made subsequently to the cooling of 
another dike, that of West Rock. It has great importance in 
this connection, since it brings into the Jura-Trias system of 
mountain-movements a dike intersecting the metamorphic rocks 
outside of the Connecticut Valley, and one that branches off from 
the southern or New Haven part of the system. 

3. THE EAST ROCK SERIES. 

The form of the East Rock area and its position between 
Mill River and the Quinnipiac, are shown on Plate II. Through 
denudation by the sea, rivers and ice, it has lost all of the 
sandstone formation that may have covered the summit, and 
for the most part that over its slopes above the 200-foot con- 
tour-line. The form of its upper portion is therefore largely 
that of the trap in its constitution — the hard rock that was 
most successful in resisting wear. This fact gives special 
interest to the larger and more detailed topographical map 
making Plate III, as will appear beyond. f 

* The rock of the dike is sparsely porphyritic ; and the feldspar distributed 
through it in crystals a fourth to a third of an inch long is anorthite, as shown 
by G. W. Hawes (American Journal of Science, III, ix, 188, 1875). This charac- 
ter makes it easy to identify the several parts of the dike; it is the only case in 
which this mineral has thus far been found in the Connecticut Valley trap. 

Percival's account of the Buttress dike and its extension southwestward is on 
page 399 of his Report. 

f The map of East Rock Park which is the basis of Plate III, was obtained 
from the Engineer department in New Haven, through the City Engineer, Mr. 
A. B. Hill. The roads of the Park from the termination of Orange St., around by 



16 The Four Rocks of the New Haven Region. 

To the north is Whitney Peak, which has already been 
described as the eastern extremity of the Mill Rock series. 
South of this and of a large area of sandstone, are East Rock 
and Indian Head, one in trap surface, but in fact the result of 
two independent outflows. To the south of Indian Head is 
Snake Rock, which also has its large trap mass, but is peculiar 
in having ridges of hard-baked sandstone that are higher than 
those of trap. The East Rock areas of trap here referred to 
are lettered on the map BB', CC'C", DD'. Besides these 
there is a more northern one, lettered AA', which lies near the 
eastern foot of Whitney Peak. 

The trap-mass AA' . — This northernmost mass, is about one 
hundred yards long. At its northern end it is only forty feet 
distant from the trap of Whitney Peak, and it is a question, 
therefore, whether it is not a part of the latter dike. But it 
is separated from it by outcropping sandstone, except where 
the interval is narrowest, and at this point there was until 
recently drained, a standing pool of water, a pretty good indi- 
cation that sandstone exists beneath, since trap is commonly 
too much fissured to hold water or afford springs. Moreover, 
the mass AA' has the trend of the East Rock series; and, 

the north to the summit of East Rock are lettered F, and the others E. These 
letters refer to two citizens of New Haven, Henry Farnam and James E. English, 
who liberally bore the expense of their construction. The topography is in part 
from the Bache Coast Survey map; but the accuracy of its contour lines was not 
sufficient for their transfer to the Park map. The heights are reckoned from 
high tide. The map is indebted to Prof. S. E. Barney, for the determination by 
leveling of the height of the highest point of East Rock, just south of the monu- 
ment (358-| feet) and also of other points on its south and east sides, and for that 
of the junction of the trap and sandstone on the west front near Orange St. bridge 
(155 feet). The height of the bolt at the Coast Survey Station he found to be 
343 feet, and the height of the top of the first step leading to the terrace about 
the monument, 355 feet. (Prof. Barney's figures are underscored on the map). 
The circuit road about the summit has a height of 320 to 350 feet; and the nearly 
parallel road on the east rises from about 216 Feet near the quarries south of the sum- 
mit, to 270 near the junction of the " Farnam drive" and " English drive," and thence 
declines northward to about 250 where it bends westward. The letters S on the 
map indicate an outcrop of sandstone in the vicinity of junctions with the trap. 

In giving the topography of the Rock, the quarry excavations on the south 
side above a level of 216 feet are not introduced, it seeming best to represent the 
Rock in its original form. They are separately mapped on the plate, at Q. 



East Rock. 17 

besides, ledges of trap along the east side appear to indicate 
that the supply of liquid rock was from the eastward, like that 
of East Rock. On this view it is the northern mass of the 
East Rock series. 

East Rock proj)er. — The trap mass BB', or East Rock, 
curves around from N. 25° E., on the north to ]ST. 75° W. at 
the southwest extremity. Adding to it the Indian Head mass, 
it ends in an east-and-west dike, and is a complete crescent in 
outline. It has a bold columnar front, in which the columns 
incline about 22° from a vertical — the position, being, as is 
usual, at right angles to the mean dip of the tilted sandstone. 
A view of the southwest front of the Rock is presented on 
Plate IV. Plate V illustrates the character and inclined 
position of the columns, and shows the contrast in the latter 
respect with Pine Rock. 

The upper 200 feet are of trap. The junction of the col- 
umnar trap with the sandstone is exposed to view at several 
points along the front. One such exposure may be seen when 
crossing the Orange Street bridge. The view in Plate IV, in 
which the bridge appears in the foreground, has the exposure 
half way up the front to the right. The height of the junction 
plane above mean tide at this place is 155 feet. Another is 
faintly indicated on the same plate directly below the Refresh- 
ment House ; the height of the junction is there 150 feet. In 
other exposures of the junction-plane to the north, the height 
is less and becomes only 85 feet near the Rock Lane bridge ; 
and it is also less to the south being but 132f feet at B', the 
southwest angle of the trap mass. Since the strike of the 
sandstone of the region is about N. 30° W., the sandstone (or 
the junction plane) has its greatest height, 155 feet, where the 
front has this direction ; and the bedding of the sandstone in 
the section for this reason appears to be horizontal. The 
diminished height to the northward is owing mainly to the 
exposures being at a lower level on the junction-plane because 
of the changed direction of the front, it becoming ~N. 10° E. 
near Rock Lane bridge. Through this interval the trap retains 



18 The Four Bocks of the New Raven Region. 

its thickness of about 200 feet. North of Rock Lane bridge 
the underlying sandstone is wholly covered by debris, so that 
the position of the junction-plane is doubtful. 

The supply of the trap forming East Rock came up, as the 
slope of its surface shows, from the eastward ; and it continues 
rising westward to the western and southwestern margin of 
the summit. The slope from the summit eastward and north- 
ward is gradual for about 300 yards, and then it pitches off at 
an angle of 45° to 50' along the course of one of its dikes. 

The position of the dike, and thereby of the supply-fissure, 
is well exhibited at he. A bare wall of trap, 50 to 55 feet in 
height, descends at the angle mentioned. Since the surface 
there exposed became solidified against the northern sandstone 
wall of the fissure, the rock is of fine-grained texture and has 
an irregularly rifted aspect. The foot of the wall is about 200 
feet above high tide, and from it the land, underlaid by 
sandstone, slopes off gently to the eastward. Since the direc- 
tion of this wall of trap is S. 15° W., or that of the movement 
of the ice over this region in the Glacial era, the wall escaped 
the tearing action of the glacier, and so retains its original 
surface. 

Farther south, along a line from d to e, there is a similarly 
steep slope, but it is made of displaced blocks of trap. At its 
base there is a fiat, terrace-like surface, which is near 200 feet 
above tide level. This steej) slope appears hence to have been 
the course of the wall of another part of the supply-fissure. 
The flat terrace, although nearly 100 feet wide, is without 
stones over its surface of either trap or sandstone except in its 
southern portion, and there occur sandstone in fragments along 
with trap, and an outcrop of sandstone over trap at S. This 
tact and the occurrence of a perennial spring in this southern 
part (at the point toward which the two paths on the map, 
Plate III, descend) make it probable that the terrace rests on 
sandstone, and that this sandstone was that bounding on the 
east, the supply-fissure above referred to. 

But there is trap again to the east of this terrace, showing 
that the lower eastern slopes were supplied from a more 



East Rock. 19 

eastern fissure. Along from c to d, the trap of the outer 
fissure appears to have flowed over and coalesced with that of 
the inner. Again south of e, the distinction of the two fissures 
cannot be made out. But the fact that the supply -fissures, 
one or both had a large inclination — not far from 45° — is 
evident from the very steep slope of the surface. 

Sections of the dikes of trap are nowhere exposed, and hence 
we are ignorant of the width of the supply-fissures. Judging 
from those of Mill Rock and Fine Rock, it may have been 
150, 200 or 300 feet ; but it was possibly much less. 

The Outflows. — In East Rock, the trap which overlies the 
sandstone along the front, was that of outflows from the 
fissures westward between layers of the tilted sandstone. The 
fact that the columns of trap have a position at right angles 
nearly to the inclined layers of sandstone is believed to be 
good evidence of this intrusion of the melted trap. 

Fig. 10 represents the view that has ordinarily been held 
with regard to the relative positions of the trap and sandstone. 




Ideal Section of East Rock before the removal of the sandstone from the summit. 

According to it the trap left the dike to flow westward 
between sandstone layers having a dip of 20° to 25°. A space 
was opened between the layers of sandstone which the liquid 
trap filled. It is plain that this chamber could not have been 
so opened in advance of the inflow ; for the hanging wall of 
the weak sandstone inclined 65° would have had no support. 
It is hence evident that the ascending stream of trap, forced 
along its course, opened a way between the layers; that a 
tongue of trap first entered, which would have been partly 
cooled against the cold rock ; but the flow was kept up below 



20 The Fou f Rooks of the New Haven Region. 

this first intruding portion until the trap had all entered, the 
lifting of the overlying sandstone going on as it # needed more 
space. This lifting would have brought a strain on the sand- 
stone that would have broken the connection between the 
lifted portion and that either side, to the northward, westward 
and southwestward. To the question, therefore, how far did 
the trap flow westward, the conditions reply : to the wall of 
such a fracture ; and it may not have extended many rods 
beyond the present limit. The sandstone of the western wall 
has disappeared in the general denudation over the New 
Haven region, excepting a small part at the southwest angle, 
where a zigzag path (Z, Plate III) ascends to its top ; the 
height of this sandstone is 185 feet, which is twenty-five feet 
above the base of the trap where highest to the northward, 
and fifty feet above that just south at A'. The locality of 
this sandstone and the zigzag path is seen on the right margin 
of Plate IV. The sandstone of the northern wall remains 
to a height of 196 feet at in : the sandstone between Whitney 
Peak and East Rock is what is left of it. The dip of this 
sandstone at m, near the junction, is 30°, in the direction X. 
73° E. ; and the inclination of the columns of the trap just 
above is also 30°. 

The theoretical section of East Rock in fig. 10 represents 
correctly the fact of the intrusion of the melted trap between 
sandstone layers. But since the bottom over which the flow 
took place is concealed from view, it is not quite certain that 
the sandstone layer on which the flow began continued to 
be the floor to its western limit. Moreover, there is a large 
discrepancy between the pitch of the trap over the summit 
and that in the section. An actual section of the rock from 
east to west (or more exactly E.S.E. to W.S.W. since this is 
approximately the direction of a transverse diameter) drawn to 
a scale, fig. 11, throws some light on these points. 

This section is essentially right in its profile, but more or 
less doubtful in its interior lines. The* height of the upper 
surface of the outflow where it left the dike at <V is 265 to 270 
feet. It was not less than this ; for we have this height for 



East Rock. 



21 



the top of the bare, unabraded wall of trap (adding the part of 
it under the Summer House west of the road). The length of 
the overflow to the present western front, is, as already stated, 
about 300 yards. The height of the western brow of trap in 
the section is 355 feet ;* and that of the bottom of the trap in 
the western front, 155 feet. These are facts ; and the diver- 
gence here from figure 10 is very great. Further, the mean 
angle of the trap surface over the summit is 10° instead of 22°, 
the mean dip of the sandstone. The latter dip is shown in 
the lines dn ; and if the floor had originally this pitch through- 
out, the thickness of the trap would have been about 450 feet, 
this being the distance on the scale of the section between dn 
and d'n', while actually it is only 200 to 210 feet. 



n. 




Section of East Rock, showing the correct profile. 

The question arises : How was the lower slope of 10° at- 
tained, and how the lessened thickness. Are they a result of 
wear by glacial or other methods ; or was the present slope 
approximately the original slope of the outflow ? A large 
amount of observation over trap ridges leads me to believe 
that the loss over East and West Kocks by abrasion has been 
small, probably not over 50 feet. The glacier, as it was shoved 
along, might easily have torn off columns from the front, but 
it would have made little impression on the exposed surfaces. 
Moreover glacial abrasion would hardly have left the highest 
points of the summit so near the western edge. 

If the outline of the summit approaches that of the original 
outflow, then — d being the lower limit of the trap on the front 

* This is the height 80 feet north of the Summit Refreshment House, just west 
of the road, this being the highest point over this northern half of the summit 
area. 



22 The Four Hocks of the New Haven Region. 

— a line drawn from d nearly parallel to the summit plane, 
would probably represent the position of the bottom of the 
outflow. The line d I" V I has been drawn on this view. It 
supposes that the trap, on leaving the dike, passed between two 
layers of sandstone from I to V and that afterward it broke 
away the layer beneath it and flowed on, either over the edges 
or surfaces of layers as the conditions favored. 

The only spot where a section of the floor or plane of junc- 
tion of trap and sandstone, is seen, is at A', the south-south- 
west corner of the trap-mass, by the road-side. There, for a few 
yards, the trap rests on upturned ledges of sandstone, and not 
on one continuous layer. The section is too short for any reli- 
able conclusion were it not sustained by facts from West Rock. 

The section, fig. 11, also represents the inner and outer 
dikes described above, with the intervening (?) sandstone. The 
doubts with regard to the widths of these dikes and the area 
of sandstone have already been the subject of remark. 



Columns stand out boldly on the steep western front of East 
Rock. But they have none of the normal forms, for the angle 
between the most prominent faces frequently approaches a 
right angle, resulting from a combination of the plane of frac- 
ture at right angles to the trap-mass and another transverse. 
The direction of these planes varies along the course of the 
Rock on account of the curve in its outlines. At the quarry, 
on the south side of the summit, at the termination of the 
zigzag path Z, there is a fine display of broad surfaces in the 
two directions "meeting nearly at a right angle. The courses 
here are about !N~. 35° E. and N. 55° W. The surface of one 
of them for many square yards is covered with rosettes of 
garnets and scattered minute crystals of magnetite, their faces 
brilliant in the sunshine. Along the whole western front 
of the Rock there is a remarkable predominance of planes 
conforming to its plane through all its changes of direction. 
This is apparent on Plate IV. and some of the right angles 
are seen on Plate V. 



Indian Head. 23 

The upper half of the columnar front (see Plate IV), down 
to a level of about 220 feet above tide-level, has columns 
four to eight feet in diameter ; below this the size is in general 
half less ; and for the lower twenty feet above the sandstone, 
they are quite small. 

Indian Head. — Indian Head is much like a small edition 
of East Rock. The length of the outflow is 100 yards ; the 
height 310 feet (313 above mean tide). A section made on 
the same principle with fig. 11 of East Rock is given in fig. 12. 

Indian Head stands quite apart from East Rock. The 
gap now separating them, where highest, is about 200 feet 
above high tide, and therefore nearly 160 feet below the top 
of East Rock and 110 below that of Indian Head, and proba- 
bly sandstone intervened for the greater part of this depth ; 
for the two Rocks face one another with steep slopes, as well 
brought out on the map, Plate III. These continue to be 



Section of Indian Head. 

steep to the very foot of each, where they approach one an- 
other down the eastern slopes. Their bases are here in inde- 
pendent valleys, designated on the map by the letters E and I, 
separated by a low trap ridge, R, so that East Rock and 
Indian Head, although the trap extends over the surface of the 
gap from one to the other, are nowhere united at base. The 
eastward sloping valley, I, lying at the northeast foot of Indian 
Head is continued in a westward sloping valley I', at its north- 
western foot, and the two together define its outline. The low 
trap ridge R, between E and I, although consisting at surface 
mostly of blocks of trap, has a solid ledge in its lower part. 
It probably crosses the gap westward ; and the Summer House, 



24 The Four Bocks of the New Haven Region. 

near 201 on Plate III, may be on its western part. The valley 
E, at the southeast foot of East Rock, is perhaps, a result of 
glacial action ; but why there should be two valleys side-by-side 
if erosion made either, is not explained. 

The trap of Indian Head rises from the bottom of the small 
valley just mentioned apparently in two half-separated streams 
instead of one even stream ; but this feature may be a result 
of erosion. The eastern outline of the trap (see Plate III) is in 
a line with the eastern of the East Pock trap, indicating that 
the supply-fissure corresponded in direction with the outer and 
not the inner of the East Pock courses of fissures. The two 
Pocks, although alike in features, are to a large degree inde- 
pendent. Abrasion helped to deepen the gap between them, 
but more by the removal of sandstone than of trap. 

Indian Head is peculiar in having a long eastward projection 
from the southern end. It is described on a following page. 

The mode of origin of the trap-masses of East Pock and 
Indian Head — by a forced flow of lava, opening through its 
uplifting action, a chamber in the sandstone for its accommo- 
dation — entitles the two to be called laccoliths. Through 
degradation, stripping them of the covering of sandstone, they 
stand side-by-side — a pair of laccoliths. 

Snake Rock. — In Snake Rock, a broad mass of trap measur- 
ing about 900 by 450 feet in its two diameters lies encased in 
sandstone. The greatest height of the trap is but 160 feet, 
and that of the sandstone west of it over 200 feet. The trap 
covers the eastern slope of the Rock nearly to its foot, thus 
showing that the supply-fissure was on that side, as in other 
parts of the East Pock series, and also indicating by its steep- 
ness that the fissure was much inclined. At the south end of 
the Rock, in the yard behind the north corner of the Basser- 
mann house, at a junction of the trap and sandstone, the dip 
is about 45° ; and this is direct evidence as to the inclination. 

The area of trap of Snake Rock has on the north the width 
of that of Indian Head ; and the mass may hence owe its in- 
creased width northward to an outflow. If so, Snake Rock 



East Rock. 25 

contains a half-emerged laccolith, its summit exposed, but the 
western wall of sandstone still standing and overtopping the 
trap. The sandstone shows everywhere the effects of hot 
vapors in all their varied forms, and before encroachments 
were made by a brewery there was a fine display of columnar 
sandstone in the southwestern bluff. 

Origin of the breaks in the East Rock series. 

The prominent breaks in the East Rock series are that be- 
tween Indian Head and Snake Rock, and that separating the 
small northern area, AA', from the main East Rock mass, BB'. 

The Indian Head and Snake Rock masses, CC and DD', 
approach one another bluntly within a hundred yards, and the 
area of sandstone between has parallel sides, as the map, 
Plate III, shows. In view of the steep pitch of the supply- 
fissure, a catastrophe to the western or overhanging wall is a 
most probable explanation of the break between them. The 
checking of so great a stream for a length of 100 yards 
might be expected to open escape-ways in some direction. 
The long eastern tail-like projection from Indian Head, C'C", 
is the result of outflow along an east-and-west fissure. The 
pitch of the fissure, as the position of the trap shows, was 
about 25° to the northward. Its southern front is steep and 
rocky, the northern, gentle and grass-covered. It may be that 
this supply fissure was the escape-way then made, and the trap 
the part of the stream that would have occupied the interval 
had no such catastrophe occurred. 

The relations of the northern trap-mass of the series, AA', 
to BB' are doubtful. Yet it is probable that the trap of A A' 
was ejected from the north end of one of the two East Rock 
fissures, or lines of fissures. The ledge of very hard sandstone 
which extends southward from near the south end of AA', passes 
by the east side of the dike- wall be ; and it probably derived 
its position and its excessive consolidation and lost bedding to 
a catastrophe that closed the fissure for the interval between 
them, which is only 200 feet wide, yet left it giving out heat, 
and generating volumes of hot vapors for the consolidating work. 

3 



26 The Four Hocks of the New Haven Region. 

The East Rock masses of trap may therefore be traced to 
two ranges of fissures. The western was the probable source 
of the most northern area, A A , and of the summit portion of 
that of BB' on East Rock. The eastern, contributed to the 
lower slopes of East Rock; and also through its continuation 
southward gave origin to the trap of Indian Head and Snake 
Rock. But for the accident to the hanging wall of the great 
fissure, the trap of Indian Head and Snake Rock would 
have made one continuous mass, and the columnar front of the 
former might have been continued over part of the present 
Snake Rock area. The areas of trap in the East Rock series 
narrow both to the south and the north. 

4. WEST ROCK. 

The facts and conclusions relating to the West Rock region 
derive prominent interest from their pertaining to one of the 
long trap-ranges of the Connecticut Valley region. The area 
is represented on the accompanying map, Plate VI, from a 
survey made by the author with chain and hand-level in 1879 
and 1880. The 20-foot contour-lines of the steep western and 
southern fronts of the Rock and the geographical positions 
are from Bache's Coast Survey map ; but the other contour- 
lines exhibiting the surface features, which required for map- 
ping detailed measurements, are those of the author." 

Features. — (1.) While the general course of the West Rock 
Range is north-and-south, the western foot of the blunt south- 
ern extremity bends round to an eastward course, and ends 
with north 30° east. The summit of the ridge also curves, in 
its last 500 yards, around to S. 70° E. or nearly to east-by-west. 
Its height in this part is 390 to 405 feet above high tide, the 
geodetic station at the extremity being 399 feet. The eastern 
foot of the ridge has no corresponding bend. 

(2.) The trap of the Rock is a continued mass instead of 
being divided into several masses through a multiplication of 

* The dotted line on Plate II is the north limit of the map, Plate VI. Heights 
G to Oa are plane-table results of Prof. II. A. Newton, from Bache's 399 as base. 



West Bock. 27 

outlets. But it lias a large bay of sandstone, of triangular out- 
line, in its southeastern portion, which from its form is called 
the Triangle. (3.) South of the Triangle there is a prolonged 
hook-like point making the southeast termination of the trap. 

(4.) North of the Triangle commences the trap of the west 
slope of the mountain. For a distance of 500 feet near the 
foot, increasing to 800 feet above, the surface of the trap is 
here elevated sixty to eighty feet or more above the level 
farther north. Moreover it is raised into rounded ridges, and 
some of these ridges have a high inclined wall on the south 
side. The first of these walls adjoins the Triangle and has a 
height of seventy-five feet, a slope of about 45° and an even 
flat surface free from marks of abrasion. Another similar wall 
farther north is thirty feet high. The smaller troughs are 
mostly one to three yards deep. The angle of sloj:>e in the 
embossed surface between the 300-foot and 100-foot contour- 
lines is less than 17° ; and in the surface north of it less than 
14°. (5.) The long, hook-like point, above referred to, is not a 
simple ridge of trap, like that from an ordinary fissure, but 
consists, as seen along its northern side (Plate VI), of a series 
of rounded ridges which increase in height to the westward, 
like those of the elevated surface of trap on the other side of 
the Triangle. Moreover, all these wrinkle-like ridges, concave 
troughs and oblique walls, have a general parallelism. (6.) 
The embossed surface north of the Triangle has lost, through 
glacial abrasion, as a consequence of its elevation above the 
general level, all of the sandstone once covering it, even to the 
foot of the mountain, excepting small portions in two of the 
troughs. Farther north the sandstone remains in some places 
nearly to the SOO-ifoot contour-line. (7.) The trap of the 
embossed area that was thus uncovered suffered little from the 
abrasion ; for the rock of the surface has the fineness of grain 
and other characteristics of the contact rock. This is true also 
of the trap of the southeast point. Moreover, in many places 
on this point below 300 feet, the trap contains imbedded frag- 
ments of the sandstone which fell into it while it was still 
liquid. The trap of other parts of West Kock ridge rarely 



28 The Four Bocks of the JYew Haven Region. 

shows evidence of abrasion below a level of 300 feet. On the 
contrary, above this level it has lost by abrasion the fine-grained, 
brittle crust-portion, and presents at surface the coarseness of 
crystalline texture that belongs to the interior of the mass. 

(8.) Another very important feature of West Rock is its 
affording a long east-and-west section through the breadth of 
a great trap range, exhibiting the contact-plane for several 
hundred feet of the outflowing trap and the underlying sand- 
stone, as described and figured beyond. 

The map, Plate VI, has the walls, troughs, and ridges of 
the surface shaded, to bring out better these features of the 
original surface of the trap. The southern front of the Rock 
has been made by degradation and hence has no shading. The 
southeastern point owes its straight outline on the south side 
to the quarrymen and the joints in the trap. The map shows 
what remained of the point in 1880. There is much less now. 

The Supply-fissure. — The inclination and width of the fis- 
sures supplying the liquid trap for the West Rock range are 
undetermined. Exposures that will afford the facts are most 
likely to be found along the eastern base of the ridge. At one 
place where the surface of trap had been uncovered but not 
abraded, which was seemingly favorable for a safe conclusion, 
the slope was 25° to 30°, and suggested the angle of 30° for 
the inclination. But the trap at the place may have been part 
of the outfloio, and not that of a dike. Observations along the 
eastern slope of the range farther north may obtain decisive facts. 

The Outflow. — The slopes of the higher parts of the West 
Rock ridge, the pitch of the columns of the western front, and 
the resemblance in features of West Rock to East Rock, lead 
to a like conclusion for the two, that the outflow was lacco- 
lithic ; in other words, that the liquid rock forced its way 
between layers of sandstone, and made the chamber it occu- 
pied. The present thickness of the mass is nearly 250 feet. 
The overlying sandstone is to a large extent the weak, chip- 
making rock of dark red and purplish color already described. 



West Rock. 29 

It is remarkable that a rock of so feeble coherence could have 
been lifted in the way mentioned. 

The questions suggested by East Rock here come up again : 
Whether the feeble slope of the surface from the west edge of 
the summit eastward to the 300-foot contour-line, and the 
small thickness of the trap, are due to abrasion, or whether the 
present conditions are nearly those of the original outflow. As 
the length of the outflow is nearly 500 yards, the mass, if 
forced up between layers dipping 25° eastward, would have 
had a much larger amount to lose by abrasion than in the case 
of East Rock.* Speculation is here set aside by the actual 
east-and-west section of the Rock which is presented along 
its southern front, and is shown in part on Plate VII, from a 
photograph. f It exhibits the trap resting, to the eastward, on 
a tilted layer of the sandstone, the dip of which eastward is 
25°. We are left to conjecture as regards the eastward and 
downward continuation of this layer to the supply-fissure 
(which the further removal of debris might perhaps uncover). 
But we know that the trap continues up this sloping layer for 

* The thickness does not admit of calculation, because the only datum besides 
the dip of the sandstone, is the height of the bottom of the trap over the sand- 
stone on the west front (about 200 feet) ; the height of the outflow where it left 
the fissure is not ascertainable. 

f The fine photograph was taken by M. W. Filley, of the firm of Bundy & Filley, 
of New Haven. The sandstone has here been exposed to view by the removal 
of the debris for macadamizing. The irregular line in the plate a third of an 
inch above the sandstone was the limit of the talus 'or debris slope; and the 
line below the sandstone is the profile of the quarry wagon road. Along the 
part of the section represented, the height of this road is ninety to one hundred 
feet. If the debris were wholly removed to the bottom of the slope, the height 
of the sandstone exposed to view would be, where greatest, over 150 feet. 

The photograph does great injustice to the view in the diminution of the 
vertical as compared with the horizontal scale, and also in flattening the angle of 
dip in the sandstone. 200 feet measured on the quarry road reaches from the 
eastern point of the sandstone section westward to within twenty-five feet of the 
line of the deep notch in the columnar front of the Rock (the place where the 
first section of sandstone ends); but this length applied vertically to the front 
above the road would make it only 180 feet in height, when in fact this 
height where greatest is over 300 feet. This error arises partly from the fact 
that the view was taken from the terrace opposite, which is only sixty feet high, 
but more from the error in an ordinary lens. 



30 The Four Rocks of the New Haven Region. 

seventy-five yards from the commencement of the outcrop. 
It conforms to the theoretical view of an outflow as presented 
in fig. 10, on page 19. 

But on reaching the end of the seventy-five yards, there is a 
change. The trap beyond rests on the edges of the layers in a 
series of ledges of the sandstone. Moreover there is but little 
rise westward along the floor; for a line drawn along the top 
of the ledges would be almost horizontal, and have therefore 
near parallelism to the surface of the trap at the summit west 
of the geodetic station. 

The following figure represents the eastern extremity of the 
sandstone for a height of fourteen feet, together with the 

13. 




base of the overlying trap. The rock is partly a hard-baked 
granitic sandstone, and partly the feeble shaly chip-making 
purplish-red sand-rock. The trap columns above the sandstone 
have in the lower part an inclination of 20°, approaching thus 
verticality to the surface of the sandstone; but, higher up 
the bluff front, there is a gradual change to 5°, which is the 
prevailing inclination.* The upper layer of the sandstone where 
uncovered shows a surface without breaks or much unevenness. 
A section of the sandstone, with the trap above, for the 
next seventy-five yards is represented in the following figure. 
The fact that the trap when melted flowed over the upturned 
edges is manifest. The chip-making rock constitutes much of 
the mass, and at its contact with the trap it is scarcely changed in 
color or texture. The trap is far more finely columnar than 
that to the east over the single sandstone layer, and probably 

* The angles of inclination here recorded are those presented to an observer 
in the front view of the rock here described. 



West Rock. 



31 



because moisture reached the trap freely from between the 
upturned layers. Other sections farther west are of similar 
character, excepting that the apparent dip is less. They may 
be followed westward along the quarryman's road for 400 
yards, when they begin to pass into the normal sections of the 
western front, that is, sections in which the lines of bedding 
are horizontal because they are in the line of strike of the 
sandstone. 



w 



w; 



•Mil 



-,,J 



V»^i'j.":\. 






■11 



i 



The question here arises : Did the flowing trap, owing to its 
movement and weight, wear off the layers of sandstone and so 
make the succession of ledges on which it rests ; or did it 
escape from its confining cover of sandstone into the open air 
and cover in its flow the exposed ledges of the region. The 
former is probably the correct view. Had the flow become 
subaerial there would have been at once a decline westward in 
the level of its upper surface ; for the level would have fallen 
as soon as the resistance from confinement ceased. There is 
no evidence of such a decline. From points on the summit 
close to the western precipice the surface for the first 300 yards 
has generally a slope eastward of 1 to 4, or 1 to 5, correspond- 
ing to a pitch of 14° to 11°. The decline is eastward ; not 
westward. Such a rise westward, even if only 5°, would be an 
impossibility except in a covered passage-way, that is, in the 
present case, one having a cover of the sandstone. Other 
evidence bearing in the same direction is afforded by the 
position of the columns along the western front, which pitch 
westward 15° to 20°. 



32 



77/ e Four Rocks of the New Haven Region. 



The summit slope eastward of 14° to 11° is less than the 
clip of the sandstone, and favors the conclusion that the 
underlying sandstone was in many places torn up by the 
heavily moving liquid trap, while left in place elsewhere. 
The floor so made consisted of alternations of wide strips that 
had the regular dip of the sandstone, with others abraded down 
to nearly flat and ledgy surfaces ; and the former prevailed 
sufficiently to determine the direction of the contraction al 
fracture-planes or the columnar structure. A reduction so 
nearly to horizontality as that shown in the south front of 
West Rock along with parallelism in the profile of the sum- 
mit may not be common. 

West Rock teaches that the section of East Rock in fig. 11, 
p. 21, may be no exaggeration. Yet it is more probable that the 
original condition was intermediate between this position and 
that indicated in this diagram. 

Sections similar to that in the south face of West Rock may 
be looked for, with some probability of success, among many 
of the trap-ranges of the Connecticut Valley wherever they 
terminate in transverse sections. All that is necessary to 
ascertain the truth is to remove the talus of trap debris. 

Three miles east of New Haven (in East Haven) a section 
was opened in cutting for a carriage-road through the second 
trap ridge west of Saltonstall Lake ; it is but a few rods west of 
the railroad station. The facts are in all respects similar to 
those of West Rock, as shown in the annexed figure. The 




trap covers a series of ledges of upturned sandstone, and 
shows no traces of displacement subsecjuent to its cooling. 
The sandstone is intersected by extensive nearly vertical frac- 



West Rock. 33 

tures, whose surfaces, owing to friction, are scratched and 
polished ; and the larger planes extend up through the sand- 
stone without any appearance of corresponding displacement 
in the trap. Moreover these polished slickensided surfaces 
have the white porcellanous coating common in the region ; 
probably made by the grinding of the feldspar of the sandstone 
in the mutual friction of the walls.* 

The trap of this ridge, at a higher level above the sandstone, 
is more or less chloritic and in many places amygdaloidal. 
Part of the amygdules are slender cylinders, two to three 
inches long and like pipe-stems in size, occurring often in 
groups — the result probably of the sudden vaporization of 
particles of liquid carbonic acid. 

In the railroad gap through the Saltonstall Ridge, the first 
west of Saltonstall Lake (" Pond Ridge " of Percival), the 
sandstone appears to lie in a similar manner unconformably 
beneath the western extension of the trap. But the section is 
now too much covered by debris for a satisfactory observation. 
Two miles east of the Saltonstall ridge in Branford, as de- 
scribed by Mr. E. O. Hovey,f the trap of a short range, the 
easternmost in this part of the sandstone region and near the 
gneiss boundary, overlies the upturned edges of the sandstone, 
and there is between the two rocks a layer of sandstone con- 
glomerate containing nodules of trap, which he attributed to 
the rubbing action of the flowing trap on the sandstone. 

These facts, ranging in this part of the Connecticut Valley 
over the whole breadth of the Jura-Trias formation, from the 

* At all the East Haven quarries, and in the ledges elsewhere exposed to view, 
these evidences of displacement and of much friction attending it abound. Frag- 
ments as large as the hand, slickensided on both surfaces and over planes of 
cross-fracture, are common; and so are walls of various inclinations hundreds of 
square yards in area. The sloping upper surfaces of the sandstone layers laid 
bare in the quarrying are sometimes polished and scratched in the direction of 
the dip for many square rods. There is abundant evidence of a vast amount of 
movement, though movement in a small way, duriDg the progress of the upturn- 
ing in which the sandstone received its universal eastward dip. 

The section represented in fig. 15 has lost much of its original distinctness by 
the sliding down of debris from above. 

f The American Journal of Science, xxxviii, 361, 1889. 



34 The Four Rocks of the New Haven Region. 

west side of the New Haven region where the trap is of the 
compact non-vesicular kind to the dikes of* vesicular trap 
toward and near the eastern gneissic border, have great impor- 
tance in their bearing on the subject of the other Jura-Trias 
ridges. The more eastern are placed by Professor Davis 
among the ridges made of horizontal subaerial flows, ejected 
before the upturning of the sandstone ; and the more western 
he has regarded as horizontally ejected and subsequently up- 
turned, although admitted to be interstitial intrusions. Neither 
of these conclusions are sustained by the facts which have been 
presented. 

The facts prove further that the era of disturbance or of the 
upturning of the sandstone was not due in any way to the 
ejection or heat of the igneous rock. The latter event, 
although so extensive, was simply incident to the disturb- 
ance ; the upturning preceded the eruptions. 

Effects of Obstructions to the outflow. — Although the trap 
of West Rock — that is of the southern part of the West Rock 
ridge — is not divided into several areas, other effects of obstruc- 
tions may be looked for, since the hanging wall of a large inclined 
fissure is Mire to have its downfalls. The gaps or notches in 
the ridge indicate incipient division, and may be among the 
effects from such a cause. They may have been produced also 
by local narro wings of the fissure through horizontal or oblique 
movement of its walls, or in other ways ; and it is a question 
whether the results of these two modes of origin can be dis- 
tinguished. The deeper and more abrupt notches we should 
be disposed to refer to the former cause. 

As the Bache map of West Rock ridge indicates by its con- 
tour lines, within a mile and a quarter of the south end of West 
Rock, there are three gaps. Two are included on Plate II. 
At the first, the height of the ridge falls off sixty feet 
in the course of 500 yai;ds. The second, situated 300 yards 
farther north, and called the "Judges' Notch'' because near 
the "Judges' Cave," is similar to the first in depth, but 
narrows more down the western front. Half a mile farther 
north is the third, called the " Wintergreen Notch." It is 



West Rock. 



35 




one of the larger gaps in the ridge. Along the summit, both 
from the north and the south, there is a descent of 100 feet, 
from a height of 440 feet to 340. Figure 16, from the Bache 
map, exhibits the facts.* The decline is gradual on the south 
side, but very rapid north- 
ward ; in the latter direc- 
tion the level of 460 feet is 
reached at the same dis- 
tance from the center of 
the gap as 440 on the south. 
This third gap is probably 
one of those caused by ob- 
structions to the outflow, 
whatever the fact with the 
others. The stream^ in 
consequence of the obstruc- 
tion, reached a height at 
the gap of but 340 feet ; 
but just beyond, the lavas 
that had been held back, made the abrupt rise in the ridge to 
440 and 460 feet. The correctness of this explanation appears 
to be sustained also by the abruptness of the rise in the 
slopes east of the gap, as the contour lines in the figure 
show, and the great breadth of the nearly horizontal area 
farther east. It will be observed also that the summit 
of the ridge north of the gap is farther to the west than 
that on the south. (Arrows are inserted to make this dis- 
tinct.) It is so because any given amount of trap depends for 
its height on the distance it flowed westward up the inclined 
sandstone layers. It may be observed that not only the height, 
460, but also 440 on the north side is to the west of 440 of the 
south side ; but the height of 440 to the north is probably pro- 
duced with a less thickness of trap. This notch is 300 yards 

* The west side of the ridge in this part, as elsewhere, is the precipitous side, 
bold columnar above. Its upper 200 to 225 feet usually consist of trap, and the 
part below of sandstone ; but the junction-plane at the Notch is concealed by 
trap debris, so that its actual height is not determinable. 



Wintergreen Notch. 



36 The Four Rocks of the New Haven Region. 

south of the Buttress dike described on a former page ; the 
position of this dike is shown on the above figure at o. 

This example will suffice for illustration. Other gaps in the 
ridge occur farther north, but they are outside of the region 
here under consideration. 

Obstructions to the outflow of lava while it was making its 
way between the layers of sandstone are also possible through 
any cause that would prevent the lifting of any portion of the 
overlying rock. The area of the Triangle has been described 
as an area of sandstone within the proper limits of the trap 
ran^e. This sandstone was not lifted like the rest of the over- 
lying stratum. Instead of this, it remained in place for the 
most part, and hence, forced the liquid rock to pass to one side 
of it. The lava, mainly took the north side ; and so the trap 
of that side had its surface raised in level above the rock 
north and became the elevated embossed area already described. 
The great sloping trap wall making the north side of the 
Triangle is the wall of an oblique fissure in the sandstone for- 
mation. Along this fissure — 45° in inclination, — the sandstone 
of the south side, or that of the Triangle, lay unmoved or 
nearly so, while that of the north side was shoved up as the 
lavas came in below. Other walls, and the small ridges both 
north and south of the Triangle, are evidences of similar frac- 
tures, in parallel directions, with analogous results. The 
unlifted sandstone was in some way put under a strain that 
produced the parallel fracturing and movements. 

The origin of the southern or western walls of West Rock 
is sufficiently explained in the remarks on this subject respect- 
ing East Rock (page 20). 

The southern front of West Rock has a columnar aspect. 
But in reality no columns stand out with the boldness they 
have in East Rock. The surface is mostly made up of the 
cleavage surface or joints that are in its plane ; and where 
there has been quarrying, these joints have great width as 
well as height. 



West Rock. 37 

3. Relation of the east-and-west and north-and-south 
fissures, and the origin of these courses. 

These two courses of fissures are so locked together in the 
New Haven region that they evidently are results of one sys- 
tem of movements. They occur together in Pine Rock ; and 
West Rock has the general trend of the Pine Rock ridge 
represented in the embossed area and the southeast point. 
Mill Rock ends to the eastward in a south-southwest fissure, 
transverse to its main course which is apparently parallel to 
the adjoining part of the East Rock trap. East Rock com- 
mences with a nearly north-and-south course, but bends around 
to east-southeast. Mill Rock and Pine Rock are not neces- 
sarily synchronous in eruption with East Rock or West Rock, 
but they belong to one epoch of disturbance. 

The origin of these courses is not fully ascertained. I have 
long explained the north-by-east trend of West Rock, and of 
the other ridges of like direction to the north, on the general 
principle that the mountain-making forces of Eastern America 
operated over any part of the area, as a general thing in the 
same direction from Archaean time onward, examples occurring 
in the Taconic and Jura-Trias elevations of the western half of 
New England. In accordance with this view the strike of the 
Jura-Trias should be that of the underlying crystalline rocks. 
It does not follow that a like dip prevails in the schists be- 
neath. It is true however that the predominant dip in them, 
and in the Jura-Trias fissures and bedding, is eastward. This 
last fact seems to favor the suggestion of Professor Davis 
that the foliation of the underlying schists has determined 
the courses of fissures in the Jura-Trias area, This sug- 
gestion would have support in the fact, were it not that in 
New Jersey, where the same is true as to the clip of the 
underlying schists, the Jura-Trias fissures and bedding dip 
westward. 

In the New Haven region, the idea of an accordance between 
direction of foliation in the schists and of fissures in the Jura- 
Trias finds no support. The West Rock ridge crosses the line 



38 The Four Rocks of the New Haven Region. 

of strike of the metamorphic schists two miles west of it at an 
angle of 20°. East Rock has an east-of-nortii course only in 
its northern extremity, and curves around through nearly half a 
circle. Pine Rock and Mill Rock cut across any probable 
course of foliation in underlying schists and do it on lines that 
differ 50° in trend. 

The origin of the east-and-west courses, which commence in 
the extremity of West Rock and continue to Whitney Peak, 
four miles, may have its explanation suggested by the remark 
under (4) on page 2. Or, it may be a consequence of the 
movement attending the production of the north-and-south 
fissures, and local to the New Haven region. The subject at 
present is one of conjectures. 

On account of the interest of the dynamical question here 
brought into view, I introduce another illustration of the 
facts from a transverse ridge only six miles north of Whitney 
Peak and Mill Rock. It is called Mt. Carmel (Plate I). The 
ridge is three miles long. It is higher than those already 
considered, the most elevated point being 736 feet above high 
tide.* But height means here, not larger accumulation of 
igneous rock or trap, but, simply, greater emergence above the 
sea-level; for this increase northward of height runs parallel 
with a like increase in the height of the metamorphic ridges 
just west ; and it is continued, at a diminished rate, into 
Massachusetts. 

Mt. Carmel has resemblances to Pine Rock. Its mean 
course is E. N. E. ; and a north-and-south trend exists in its 
western part. But the north-and-south portion in Mt. Carmel 
is a large feature in the ridge and has direct continuity with 
the east-northeast portion. 

The ridge is divided by a very deep and open gorge, into an 
eastern and a western section. The gorge is often called the 
"Neck," and the high summit adjoining it on the west, the 
" Head " of the " Sleeping Giant " — a name suggested by the 
form of the ridge as it appears lying on the northern horizon. 
Both have northern and southern slopes of sandstone, the 

* According to the leveling of two parties under Mr. Bache. 



lit. Carmel. 39 

southern going about half way to the top above its base, and 
the northern reaching a greater height. 

The western section, while high and massive at its eastern 
extremity, falls off rapidly to the westward, and in half a mile 
is reduced to a narrow trap ridge not exceeding 100 feet in 
height above the adjoining country. Through this part within 
300 yards, pass Mill River, a north-and- south carriage road 
(N. 20° W.) without change of grade, and, a few rods farther 
west a railroad. Along the railroad, and between the carriage 
road and the river, the course of the trap changes from about 
north-and-south to N. 10° E. ; and as it crosses the river to 
N. 20° E. Thence it continues on to the summit, widening 
and increasing rapidly in height and curving • still farther 
eastward. 

At the section in the railroad cut, the trap is seen resting on 
its south wall of sandstone, the wall dipping about 45° — appar- 
ently indicating that the dike has this pitch. Between the 
carriage-road and Mill River, the north side of the trap has in 
many places a westward dip of the same angle, confirming the 
conclusion from the railroad section as to the large dip of the 
fissure. It is thus proved that the western section is a con- 
tinuous mass of trap of gradually changing course and mag- 
nitude ; and that it is strictly " transverse " in direction only 
along its eastern end. It is a dike to the westward and probably 
so throughout. 

The eastern section is made one continuous mass of trap by 
Percival, and one also with the western portion. It is divided 
from east to west, as he states, by a valley, and in the valley 
there is a spring giving out a streamlet which flows northward. 
There are gaps in both the southern and northern sides, divid- 
ing them into a series of elevations. These elevations are 
indicated on Percival's map, so as to look as if he regarded 
them as separate dikes ; but this is contrary to the description 
in his Report. I have looked for sandstone in two of the gaps 
of the south side, east of the " neck," and have found evidence 
in each that the trap is continuous, and descends in these gaps 
nearly half way to the base of the mountain. In the east-and- 



40 The Four Rocks of the New Haven Region. 

west valley the spring and streamlet are probable evidence 
that there is sandstone beneath ; and on this ground, it may 
be that there are, in this eastern part of Mt. Carmel, two 
parallel east-and-west dikes. 

Mt. Carmel appears to be a combination of dikes, without 
the "buried volcanoes" supposed to exist there by Professor 
Davis. In the view from the west side of Mill River there 
are in sight nearly 600 feet in height of massive trap, having no 
subdivision into sheets or layers, and nothing to suggest the 
idea of lava-streams in the depths below. 

The union in this small ridge of approximately north-and- 
south and east-and-west courses is further proof of their 
mutual dependence in the system of movements attending the 
Jura-Trias mountain-making of the Connecticut Valley. But 
its origin remains unexplained. 

Concluding Remarks.— A review of the principal conclu- 
sions in this paper is given in its introductory remarks (page 
5), and a recapitulation here is therefore unnecessary. 

The reader may have been led to the idea that the author 
would make the West Rock Ridge typical for other ridges of 
like features in the Connecticut Valley region, in disagreement 
with the conclusion of Professor Davis who holds that in the 
case of most of these ridges, if not of all, the trap was poured 
out in one, two or more horizontal sheets, separated, and over- 
laid horizontally, by beds of sandstone, and that the whole was 
afterward faulted and tilted so as to make the ridges. The 
author acknowledges that he is inclined to make the conclusions 
he has reached general. He, however, admits that he has 
not made the structure of the other ridges of the valley a 
special study. He believes his observations sufficient, however, 
to authorize the statement that a more intimate knowledge of 
the facts is required before any adverse views can be regarded 
as established. 



WALKS AND DRIVES. 



Several reasons have induced the writer to publish in this 
place the following scheme of Walks and Drives. 

The region of New Haven is remarkable for the variety and 
attractiveness of its scenery. The " Four Rocks " standing 
about its inner precincts, the distant background of forest- 
covered ridges on the west, north and east, the three rivers and 
the lakes, the city spreading widely over the plain, the Bay, the 
Sound with Long Island on the southern horizon, make an ever- 
varying and ever-charming landscape. 

It is therefore most desirable that the citizens of New Haven, 
and especially the young new-comers, should know where to go 
for a pleasant walk, what is to be seen, and how long the way. 
The exercise thus obtained is the best possible for the reasonable 
athlete who has health, and not victory alone, in view. Pursued 
systematically, it would become a habit and afford pleasure and 
physical good through a life-time. 

Besides scenery, there is instruction to be gathered from 
nature by the way. There are rocks, and there are flowers and 
animal life of the land and of fresh and salt waters, to re- 
ward those who are interested in what is behind the scenes. 
The rocks stand up to be looked at, and also to answer the 
enquiry as to their origin and history. As information on this 
latter subject is thought worthy of attention in these days, is 
exalting to the appreciative student, and is especially varied in 
the vicinity, the author has desired to make the New Haven 
region a source of instruction to teachers and students, and to 
all lovers of science and scenery. 

The Walks and Drives are enumerated in a circular order 

from East Rock around by the left. The walks may often be 

shortened at option by taking the horse-cars. The distance from 

the center of the city square to the four Rocks is 2£ to 3 miles ; 

4 



42 Walks and Drives about New Haven. 

to the Yale Athletic grounds, out Chapel Street and Derby- 
Avenue, \\ miles ; to Allingtown, 2 miles ; to. Savin Rock, on 
the Sound, 4 miles ; to the Old Light House, on the east cape 
of the harbor, 5^ miles; to Tomlinson's bridge, \\ miles; to 
East Haven village, 3^ miles ; to the bridges over the Quinnipiac 
in Fair Haven, a little over If miles ; to Whitney Lake Boat 
House, 2-]- miles. 

The variation of the compass at New Haven is 9i° westerly ; 
whence N. 45° E. compass course is N. 35-£° E. ; N. 10° W. 
compass course is N. 19^° W. 

On the map the parts colored red are those of the trap ; the 
rest of the region is underlaid by sandstone. 



1. To East Rock — A Walk or Drive. 

The best route for the first visit to East Rock is by Orange 
Street and the Farnam drive (the road leading north from the 
Orange St. bridge). It is the best for the succession of views 
and for the study of the features of the Rock. The views are 



1. Profile of Mount Carmel. 

greatly varied in consequence of the complicated structure of the 
Rock (Plate III) and the boldness of its outlines, together with 
the nearly universal covering of forest. There are hence shady 
recesses as well as distant landscapes. Moreover these land- 
scapes are widely diverse on account of the position of the Rock. 
To the west are Mill River, with the long and winding Whitney 
Lake, the city in a forest of elms, the harbor, and the West 
Rock ridge and the Woodbridge heights as the western bound- 
ary. On the east lie the green meadows of the Quinnipiac, as 
large as the New Haven plain, bounded along the horizon north 
and east by trap ridges in long succession ; and although simple in 
its elements, the landscape is one of the finest which the Park 
affords, especially as seen on the road northeast of Whitney 



Walks and Drives about New Haven. 43 

Peak. Mt. Carmel, or " the Sleeping Giant," lies on the 
northern horizon, with lower ridges westward to the Bethany 
Notch and West Rock. To the northeast is Lamentation 
Mountain, with a bold western front, not far from Meriden ; 
then southward, come Higby mountain between Meriden and 
Middletown, Mattabeseck mountain against southern Middle- 
town, and the three Durham mountains, (the middle of which, 



2. Profile of the three Durham trap-ridges, Tremont in the center, and 
Pistipaug trap-ridge to the right (south.) 

having three peaks, is the Tremont of Percival); then, Pistipaug 
ridge on the east border of Pistipaug Lake, the long even-topped 
Totoket range in North Branford, and last, Saltonstall ridge, 
bordering Saltonstall Lake ; and in a nearer range, directly east, 
the rounded summit of Rabbit or Peter's Rock, noted for its 
large and nearly vertical columns. They derive interest from 
the fact that all are trap ridges, and of the same epoch of 
eruption with East and West Rocks. 

The positions of these trap ridges are indicated on the follow- 
ing map of the trap-areas of central Connecticut south of the 
latittide of Hartford (H), from Percival's Geological Report of 
1842. The Saltonstall line is seen at S abreast of Saltonstall Lake, 
the Pistipaug, against Pistipaug Lake, and Lamentation Mountain 
northeast of M, Meriden ; and from these points and the profile 
in fig. 2, the others of the series on the east are easily distin- 
guished. 

Northwest of M, are the Hanging Hills, the commencement of 
the line that extends to Mt. Tom, in Massachusetts. At w is 
West Rock, the south end, it is seen, of a long curving line which 
dies out just west of the Hanging Hills of Meriden. At e is 
East Rock, an isolated ridge. At c is Mt. Carmel, apparently a 
group of trap-areas, but really for the most part a single area 
having several elevations. Along mn, and op, are the eastern 
and western boundaries of the Red Sandstone region. Middle- 
town (N) is near the eastern. 

The view of East Rock from the vicinity of Orange St. bridge 
is shown in Plate IV. Its battlement-like front is well set off 
by the foliage about it. The large columns appear to rise 
vertically from deep foundations ; but they have really an 



44 



Walks and Drives about New Haven. 



inclination eastward of 20° to 23°, as may be seen in profile 
views. Moreover, half way to the summit — correctly at a height 
of 155 feet — the bottom of the columns may be seen resting on 
a bed of grayish and reddish sandstone ; but the columns in this 




Trap-areas of Central Connecticut: From Percival. 

lower part are small. This outcrop of sandstone may be reached 
by a rough path over the stones. But, although delicate feet have 
trod it, most will be contented with a sight of some lower layers 
of the sandstone formation just opposite the end of the bridge. 



Walks and Drives about New Haven. 45 

There is, however, a difference in the interest of the two out- 
crops. The sandstone of the upper outcrop was directly beneath 
the melted trap at the time of the ejection and became hard- 
baked by the heat. The lower was too far away to be much 
changed ; for heat in rocks travels but a short distance from 
its source unless there is much moisture at hand to be converted 
into steam for its distribution. Nearly on the same level (150 
feet), there is another place, a little east of a vertical line through 
the Refreshment House of the summit, where the junction of 
the trap and sandstone is open to view. But it is not intelligible 
from below, and is reached with some difficulty. 

A short distance north of the Oi-ange Street bridge, trees and 
shrubbery have gained a foothold up nearly all the steep front ; 
and here Tyndall, in a solitary walk in the winter of '72-'73, when 
snow and ice covered the cliffs, climbed to the summit — no great 
feat for the Alpine climber, but still much enjoyed. 

Continuing northward beyond Rock Lane bridge, the sand- 
stone crops out at intervals. Soon, trap has its place, and grows 
bold toward Whitney Point and its Summer House. Then 
comes in again the sandstone. The circular plot of land in front 
of the Summer House has trap over its southern half and sand- 
stone over the northern ; and the hard light gray portions of the 
latter are in some places greenish from the presence of a little 
epidote. These transitions from sandstone to trap, and the 
reverse, are indicated on the map of East Rock, which shows, 
by the red color, that the Whitney dike has here been passed. 
Other such transitions may be seen on the way, and the map 
is referred to for their explanation. 

Outside of the stone parapet on the road where the height is 
254 feet (see map) a bare wall of trap descends at a high angle 
toward the depths from which, miles below, it originally came 
up melted. It is exposed to view for a height of 50 to 60 feet. 

At the summit of the Rock, the view off on a fine day is 
charming. But although at the top, it does not include the 
country on the east or north, unless an ascent is made within the 
narrow shaft of the monument. The people's tower for a pano- 
ramic view, of ample dimensions, with broad and easy stairway, 
a landing above large enough for scores at once, and no higher 
than is necessary to afford a view clear of obstructions, has not 



46 Walks and Drives about New Haven. 

yet been made. A good site for it, and one very nearly as high 
as that on which the monument stands, would bo the high ground 
a few rods south of the Refreshment House, where it would look 
well from below if suited in style to the foundation. 

On the descent, return to the loop in the road, at a height of 
268 (Plate III), and there take the "English Drive," going 
southward. On rounding the steep southern side of the Rock, 
between the heights 227 and 216, Quarry Corner is passed, 
where quarrying was pushed vigorously when the question of 
taking possession of the grounds for a Park by the city was pend- 
ing. The deep gashes however have made a fine display of the 
nearly vertical joints or divisional planes of the rock, (resulting 
from contraction on cooling,) and opened a broad south west ward 
surface that glitters brilliantly in the sunshine from the rosettes 
of garnets that cover it. There were formerly minute octahedrons 
of magnetite also, but the latter have mostly disappeared. The 
descending road passes 201 and a Summer House between East 
Rock and Indian Head, and then makes nearly the complete cir- 
cuit of the latter, passing along its western face above the base 
(concealed by debris) of the columns Approaching 103, it goes 
over the trap of the southwest angle of East Rock. Thence it 
winds around to Orange Street bridge. 



2. To Indian Head — A Drive ok Walk. 

The route from State St. over Snake Rock to the summit of 
Indian Head takes in the roads not passed over in the previous 
excursion. Leaving Snake Rock the road passes under a bridge 
and comes up by the bold southern front of Indian Head. This 
steep, rocky front, it may be observed, continues eastward below 
the road, and is part of a long, tail-like extension of the trap to 
within 100 feet of the carriage road at the foot. It is a good 
place for further exploration when there is time for it, for it is 
a peculiar feature of Indian Head, as the map shows. The road 
continues along the east side and commences the ascent to the 
summit at its northeastern angle. 

The view from the southern side of the summit, near where 
the road stops, has the forest-covered Snake Rock in the fore- 



Walks and Drives about JVevj Haven. 47 

ground, and brings nearly the whole New Haven plain, from 
Fair Haven on the east to the remotest limits of West Haven, 
into one broad landscape. A path leads to the higher summit. 
From the brow of the Rock the view is much like that from 
East Rock, but the bold front of East Rock adds an impressive 
feature. At one point, East Rock may be seen projected upon 
West Rock, one over the other, like the faces in a medallion. 

Indian Head takes its name from a group of trees at the 
summit, which in former time, as seen from below, looked much 
more like the tuft on the head of an Indian than it does now. 



3. To East Rock — A shady Walk. 

Take the path near Whitneyville over the Foot-bridge. When 
approaching and crossing the bridge there are pleasing views 
both up and down the river. The path leads to the road and 
thence is continued across it up to the Hemlocks, one of the rest- 
places. The rock along the way up and at the Hemlocks is 
sandstone. The valley just north takes the drainage of the 
hills, and at its narrower end (at a, Plate III) it formerly had a 
standing pool of Avater. A well has been sunk at this place to a 
depth of 18 feet in sand, which has 6 feet of water. The trap 
area, AA', is on its east side. Along the road west of it, after 
some sandstone, the rock changes to the trap of Whitney Ridge ; 
and a little farther northward the precipitous front of the peak 
may be seen high up amid the foliage. Although so grandly 
bold, sandstone will be found at its base a few yards east of the 
road. South of the Hemlocks, at the first eastward bend near 
191, there is the end of the sandstone in that direction in a little 
valley, and just beyond, the trap of East Rock is in full force. 

From the Hemlocks a path leads off southeastward, which 
reaches the road again at a point near 254 (Plate III). About 
100 yards out on this path take the branch path eastward toward 
a quarry in a low ridge of hard-baked sandstone, and near the 
quariy a path southward which crosses the low ridge and comes 
down to the foot of the trap wall referred to on page 45. Trees 
and shrubbery mostly hide the wall ; but just south of a juniper 



48 Walks and Drives about JVew Haven. 

bush there is an opening through which it may be approached. 
It is well to examine it and see the evidence that the steep wall 
of trap is the outside of the dike ; that it was cooled against a 
cold wall of sandstone — the east wall of the fissure up which the 
melted rock came. The sandstone at the foot of the wall is 
concealed by the soil. That which covered it above was proba- 
bly carried away by the glacier, which thus left it bare, as we 
now find it, but, as stated on page IS, did not disturb or abrade 
the trap. To the eastward is a fine view of the Quinnipiac 
meadows and the trap ridges on the horizon, commencing on the 
north with the Durham three. The path now leads southward 
up the slope over a surface of trap (Plate III), and soon reaches 
a spring, or water in the course of a little stream ; and then a 
level plot of land, terrace-like, free from stones, with a very 
steep upward slope between it and the road. At the southern 
end of this terrace another and better spring will be found, a 
little below the level of the terrace. Along the path, a few rods 
below this spring, sandstone outcrops against the trap — the sand- 
stone in pieces as the glacier left it (at S, Plate III) ; and just 
north and also east of the spring, a few rods, some fragments of 
sandstone lie over the surface. 

From the spring, take the path leading southward up to the 
road at 238, and continue on around the steep southern side of 
East Rock toward 216, passing Quarry Corner and Garnet Bluff. 
The nearly rectangular intersections of the two systems of joints 
should he observed and the glittering surface of garnet rosettes 
on one of the fronts trending southwest ; but please leave the 
garnets to shine ; a hammer will only destroy them. 

Here a shady zigzag path descends to the road, and just below 
the road is continued to Orange Street bridge, passing an excel- 
lent spring on the way. 

Except for a short distance at the top, the rock along the 
zigzag way down is sandstone ; and it is an upper portion of the 
sandstone which underlies the trap ; so that here the trap is 
laced by sandstone up to a height of 185 feet — the height of the 
broad area at its top. (Plate III, and page 20). 

Another way down is by a path leading from 227 to the road 
below at 201, and thence by another path to the road and 130, 
where a branch of the zigzag path above-mentioned commences 



Walks and Drives about New Haven. 49 

its descent. The succession of sandstone, trap, sandstone, just 
above 130, merits special attention, since it is a cut through the 
southwest corner of the East Rock trap for which Science is 
indebted to the constructors of the Park. 



4. To THE SUMMIT OF WHITNEY PEAK A SHADY WALK. 

Take again the path which crosses the foot-bridge near Whit- 
neyville. On the east side of the bridge follow the path north- 
ward nearly to the Factory Grounds before making the ascent 
to the road. The road is reached near the Summer House on 
Whitney Point, and the path to the summit ascends from it. 
If the north and south junctions of the dike with the sandstone 
have not been already observed, it will give interest to the walk 
to look for them : first on the plot near by encircled by the road; 
and then, for the sandstone of the southern wall, about 100 yards 
down the road on its east side. Moreover, between these limits, 
the trap at one place on the roadside looks decomposed, and has 
in it along a vein a white mineral which is laumontite. 

The path up goes first over trap, and then, for a short dis- 
tance, over the sandstone of the northern wall. There are 
various views along the way ; but the summit is a solitary place, 
shut in by the trees, and many will enjoy it the better for this 
unusual feature. 

On the side north of the summit there is a nearly vertical 
precipice of 70 or 80 feet, which has interest besides that of its 
own features from its having been laid bare by the glacier. The 
sandstone was easily removed by the moving ice, but not so the 
wall of hard trap. 

The return may be made by the path that winds around 
southward, and joins that descending from the Hemlocks. 



5. Abound Mill Rock and among the Kettle-holes of the 
Pine Marsh region — A Drive or Walk. 

Out Prospect Street, noted for its fine western prospects. The 
road rises above the general level of the plain along the western 
slope of Sachem's Ridge — a sandstone ridge thinly covered with 



50 Walks and Drives about New Haven. 

earth, and a little over 150 feet above tide-level where highest. 
The distance from Grove Street to the Rock is. just two miles. 
Prof. Marsh's grounds are passed on the left, a little over half a 
mile from Grove Street; the Observatory, on the right 300 yards 
farther on ; and the Reservoir, also on the right, at l£ miles 
from Grove. Along the road, the distant part of the western 
view includes the Woodbridge Heights, the long West Rock 
Ridge and Pine Rock. Beyond Canner Street — that on the 
north side of the Observatory Grounds — over an open field on 
the west, Pine Rock is in full view with West Rock Ridge 
beyond it ; and Wintergreen Notch is seen over the western 
flank of Pine Rock. At the next crossing — that of Highland 
Street — the rival Rocks afford contesting pictures in the opposite 
directions — West Rock, a profile ; East Rock, a front view. 

Reaching Mill Rock, turn west into " Mill Rock Street," and 
take the first road going northward. It passes the west end of 
the Rock, where is to be seen the section represented on page 1 1. 

Go on to the second east-and-west road. Between this road 
and Whitney Lake in a northeastward direction, near the borders 
of that remarkable depression, like the channel of a great river, 
Pine Marsh Creek, are many " kettle-holes." (The position of 
the Pine Marsh depression is shown on Plate I, and its southern 
extremity near which there are other large kettle-holes, on Plate 
II.) Along the route northward to the next road, the kettle- 
holes are under the pines within fenced property, and in driving, 
a road a third of a mile east must be taken. Beyond this, a road 
may be followed (commencing a little to the west) through the 
forests to the lake. The bridge over Mill River here reached 
may he crossed and the return made along the east foot of East 
Rock ; or the road directly south may be taken to the east end 
of Mill Rock and Whitneyville. 

In the earliest colonial times the fall of water at Whitneyville 
was made useful in turning a grist-mill, and as far back as 1642 
it was " ordered that there shall be no other mill built for this 
town, provided that the mill that now is, be fitted so that it may 
serve the town's occasion to grind both Indian and English corn 
well." Tims the stream early became " Mill River." 



Walks and Drives about New Haven. 51 

6. To Mill Rock— A Walk. 

Out Prospect Street, noting the outcrop of coarse sandstone 
or conglomerate on the eastern road-side, occurring for 250 yards 
after passing the residence of Prof. Dexter, and also another 
exposure of the rock beyond the Observatory Grounds. At the 
latter locality the eastward dip is plain, and some of the included 
stones are 6 or 8 inches in diameter. Not more than 6 or 8 feet 
of earth generally cover the sandstone of Sachem's Ridge, and 
this is for the most part bowlder clay or till, a deposit of the 
glacier. The scattered stones or bowlders on the surface are of 
glacier transportation. Nearly all are of trap or sandstone, the 
rocks of the valley, a few are of quartzyte, and one or two of 
gneiss. At Harrison Street, the first street beyond Highland 
Street (and the first south of the Reservoir), turn west to the 
next north-and-south street, Winchester Avenue. When 100 
yards on the way down Harrison Street, there may be seen, in 
the field to the south, ] 00 feet off, a large bowlder. Its length 
is 14 feet and its probable weight 40 tons.* The glacier may 
have taken it off from Mill Rock ; but more probably from a 
ridge near or beyond Meriden ; for the trap is like that of the 
largest of the New Haven bowlders. The bowlder is split in 
two longitudinally, and the parts separated 7 inches. The chief 
agent in the splitting was a small oak, which began as a seed in 
a crevice. The tree has been cut down, but a large crop of 
stems have started up from the trunk. 

Continue on Winchester Avenue northward to the west end of 
Mill Rock. Here the dike may be seen in its full breadth 
between its walls of sandstone, nearly 210 feet apart. The 
inclination of the rude columns may be noted ; the south wall 
of sandstone adjoining the dike examined for its shining steel- 
gray scales of hematite, (the place has afforded also garnets) ; 
and also a vein near the middle of the dike, for its laumontite, 
and another for prehnite (p. 11). 

* The calculation is made thus: 32 cubic feet of water weigh a ton (of 2000 
pounds). The specific gravity of the solid trap of West Rock is about 3-03 
(Hawes), but of the mass of rifted trap of the bowlders, probably not over 2 9. 
Hence the latter should give 32 -5- 2 9 = 11 cubic feet to the ton ; the former 
32 -=- 3 =10-67 cubic feet to the ton. Consequently a bowlder of the former of 
440 cubic feet should weigh about 40 tons. 



52 Walks and Drives about New Haven. 

Take now the road by the south foot of Mill Rock eastward to 
the end of Prospect Street. Close by, a quarry road leads up 
the slope to an old trap quarry. From the summit, north of the 
west end of the quarry, there is a fine view of Mt. Carmel and 
the ridge which extends from it westward to its junction, at 
Bethany Notch, with the West Rock Ridge. At the quarry, 
the mineral prehnite used to be obtained in good specimens. 
The junction of the trap with the sandstone of the south wall 
may be looked for south of the east end of the quarry. 

Continue eastward along Armory Street to the height of 
ground between Prospect Street and Whitney Avenue. Here 
cross the field northeastward to a low bluff of trap where there 
was once a small quarry. This is the beginning of the dike B B' 
(page 11); and in the high sandstone bluffs northwest of it. is 
the narrow dike, C. The house just beyond the west end of this 
bluff is the residence of Prof. Wm. P. Blake, geologist and 
mining explorer, who has travelled extensively over the mining 
regions of the Rocky Mountains and California. Ascend the 
low ridge at the old quarry, and a path will be found leading 
through the woods northeastward to the Whitney Lake Boat- 
house, dust above the north end of the ice-houses, a few feet 
west of the road where sandstone makes the roadside, there is an 
outcrop of trap, which is not too large to be that of a half-buried 
bowlder. But Prof. Blake, when his road just north was in 
process of construction found that it was continued, northward 
across the bed of the road, as a dike 5 or feet wide. Its course 
is N. 35° W., which is nearly toward the trap-area I) (Plate II). 

By the roadside abreast of the lake, below Mr. Day's store, 
there is a pot-hole in the sandstone which is a record of the 
Glacial flood. When cleared of the rubbish it was ascertained 
that ils depth, measured from the highest traces of it on the south 
side, had been 7 or 8 feet. It was made through the whirling 
of stones by the rushing waters of flooded .Mill River, when the 
waters were 60 feet or more above tide-level. The north side of 
the Mill Rock Ridge was here the west shore of the stream. 
Some of the large stones are still inside the pot-hole. Two 
similar pot-holes were cut away at the last grading of the 
road not far below. The flood was made by the melting of the 
great glacier. A hue terrace, north of the ice-houses, registers, 



Walks and Drives about New Haven. 53 

approximately, the height of the flood along that part of the 
stream — 63-66 feet ; and the terrace southwest of the Whitney- 
ville factory, the site of fine residences, shows that the waters 
there stood at 20 feet above the level of the present dam. The 
road of Whitney Avenue rises nearly to the top of this terrace as 
it leaves Whitneyville. 

Toward the extremity of the Mill Rock Ridge, the junction of 
the trap and sandstone may be seen, and, along it, the fine- 
grained texture of the trap and the short distance to which the 
sandstone is hard-baked ; and, by going to the top of the dike, 
the inclination of the columns may be noted and the little 
apparent width of the dike (p. 14). At the point, there are 
traces of a laumontite vein, like that at the west end. 



7. To Pine Rock — A Walk or Drive. 

The most instructive route to Pine Rock is by Goffe and 
Crescent Streets ; it reaches the Rock at its west end : distance 
2f miles. The east end is 3 miles distant by Dixwell Avenue 
and Arch Street ; but this route may be shortened by taking a 
Shelton Avenue car to the termination of the track, and then 
continuing north a block to Morse Street, then turning west. 
Morse Street is nearly in line with Arch. 

Crescent Street passes by the west side of the Beaver Pond 
Meadows. These " Meadows " occupy a remarkable depression 
in the New Haven plain, over a mile long and several hundred 
yards wide. The small stream is supplied from subterranean 
sources ; and at some points in it the water never freezes, not 
even when the thermometer falls to zero. Until recently it has 
been more a surface of marshes than of meadows, and an excel- 
lent botanizing ground. 

Besides the great depression, several " kettle-holes," 50 to 100 
feet or more in diameter, may be seen on the west side of Crescent 
Street (see Plate II, for these and many other kettle-holes). On 
passing by the end of Dyer Street — the first street that enters 
Crescent Street from the west — a remarkably fine " kettle-hole " 
will be found north of Dyer Street ; it has water at bottom on a 
level with the water of the Beaver Pond depression. Half a mile 



54 Walks and Drives above New Haven. 

north the outlet of the brook is passed. It flows westward 
along a channel in the plain wide enough for a great stream, and 
empties into West River. The fall of the waters and the 
amount have been sufficient to supply one mill and give half 
supply to one or two others. By cutting down the outlet the 
meadows will be to a great extent drained. The depth of the 
Beaver Pond depression east of the outlet, down to the bottom 
of the soft earth or mud, is 25 feet below mean tide. 

In sight of the facts, the question as to origin presses : why so 
large a depression here when nearly all the rest of the New 
Haven plain was built up to regulation height ? 

A suggestion: it may be that along its course the depression of 
the surface was so much deeper than elsewhere that the sand and 
gravel from the glacier, deposited by the glacial flood, did not 
succeed in filling it ; further, that the depression was made by 
the glacier in the Glacial period or that preceding the flood ; 
that the glacier, moving S. 15° W. through the gap between 
Mill Rock and Pine Rock, and being 1000 feet or more thick, 
ploughed deeply into the soft sandstone below ; that it thus 
made the Pine Marsh Creek depression, north of Mill Rock, and, 
after a partial interruption, the Beaver-Pond depression ; and 
that it kept on the work of excavation southward to the Bay, 
making the channels of East Creek and West Creek. Plate II 
shows the south end of the Pine Marsh depression at Pi, and the 
positions and extent of East and West Ci'eeks ; and it also 
illustrates the fact to the eye that the kettle-holes are a part of 
the results, since they are connecting links between the greater 
depressions. These interesting natural features will soon dis- 
appear through the conversion of the meadows into a city park. 

Directly west of the meadows rise the Beaver Hills, to a 
height of about 100 feet. This elevated sandstone region, like 
that of Sachem's Ridge, is plain evidence that the glacier for 
some reason failed to excavate along it. The reason is found in 
the existence of a resisting trap dike just north for each of the 
ridges. If in planing a board the cutting edge strikes the head 
of a nail and has a notch made in it, the surface of the board 
beyond the nail will have a little ridge on it corresponding to 
the notch. So the glacier was notched by the trap ridges, and 
the Heaver Hills and Sachem's Ridge are the little ridges con- 



Walks and Drives about New Haven. 55 

sequently left on the surface of the New Haven region ; and the 
direction of these ridges shows the direction of the movement of 
the glacier. Other sandstone ridges also were shaped by glacier- 
planing. 

Reaching the end of Crescent Street, next take Wintergreen 
Street, a few rods south, to the west end of Pine Rock — where 
the small trap dike A (p. 7), is in sight. The road along the 
southern foot of the Rock (which is poorly passable for wheels) 
leads to a point abreast of the gap, between B' and C, where a 
path offers the best way of reaching the top. At the summit of 
the gap the strange northern hills of trap, E E', which make the 
head and neck of the duck-shaped dike, may be explored. On 
the way eastward to the highest point of the Rock, the bare 
northern wall of the dike, 50 feet in height as left by the glacier, 
is worth seeing ; and still more the fine view from the summit. 
Just west of the highest point a surface of trap sloping south- 
ward has the pitch of the columns. 

The descent may be made by the east end of the Rock. At 
this east end the trap and sandstone of the northern wall may be 
seen in contact, the latter very hard from the heat to which it 
was subjected. In the quarry, just south, several minerals may 
be collected (p. V), and the laminated appearance of the trap 
may be well observed. On the low part of the northern slope of 
the Rock, there is a fine spring. 

The "cave" at v is one of the interesting spots about the Rock, 
because of the exposure in its roof of the southern wall of the 
dike and the view of the oblique columns above it (p. 8). It 
may be best examined before making the ascent of the Rock. 

On the retui-n from Pine Rock take the road at the east end, 
leading southward and eastward by Arch street to Dixwell 
Avenue. It crosses the northern part of the Beaver Pond 
Meadows. 



8. To Mount Carmel — A Walk or Drive. 

Mt. Carmel (Plate I) is about six miles north of Whitneyville. 
As the profile on page 42 indicates, it has three gorges on the 
southern side of its summit. The western or that of the Neck 
of the " Sleeping Giant," is the deepest and has a precipice of 



56 Walks and Drives about New Haven. 

200 to 300 feet facing eastward. The other two — the second, 
and third — are between 100 and 200 feet in depth. The highest 
point of Mt. Carmel is not on the " Head," but on an isolated 
peak a little north of the second gorge. For the ascent of Mt. 
Carmel take the road eastward, and to reach the Neck turn into 
the field just after passing the first road on the right ; for the 
second gorge turn in at the bridge after passing the second road; 
for the third notch turn in just after passing the third road. 

If the object of the excursion is to take the view, it is best to 
ascend the " Head," which has a path to its summit. But for a 
longer and more interesting trip, including a visit to the geodetic 
station and highest point, the path should be soon left and a 
climb made over the broken rocks to the top of the east side of 
the Neck — from which also there are fine views southward. 
Going eastward along the summit the second gorge is reached. 
It has a bold bluff along its northwest side, and just opposite, 
rises the highest peak, that of the geodetic station of the Coast 
Survey. To reach it a descent must be made into the gorge and 
a climb on the other side. Descending northward the central 
depression of the mountain is reached, with its small run of 
water and a spring at its head. This excursion may be extended 
farther east, and the descent made toward Wallingford ; or the 
return may be made down the second gorge. On the descent by 
this gorge about half-way down comes the change from trap to 
sandstone. Just before reaching the sandstone, the trap is finely 
glacier-grooved in a north-and-south direction, and one of the 
grooves is 2 feet wide and 6 inches deep. The sandstone below 
the trap affords intei'esting specimens of the yellowish-green 
mineral, epidote. Much of the sandstone about the mountain is 
a coarse conglomerate. 

After descending, if not done before making the ascent, the 
trap along the railroad and from there to the river should be 
examined, as it is the low western commencement of the great 
mass which makes the " Head." At the railroad, on the west 
side of the cut, the trap rests on the sandstone, as stated on page 
39 ; and, on the east side, great masses of sandstone are included 
in the trap. 



Walks and Drives about New Haven. 57 



9. To Centerville and the Gap at Mt. Carmel Village ; 
A Glacial Excursion — A Walk or Drive. 

The narrow gap at Mt. Carmel village, by the west end of the 
mountain, about 250 yards wide, has the lofty " Head " of Mt. 
Carmel on the east, and lower bluffs of trap on the west. The 
only spots that are free from the trap, and therefore level, afford 
scant room for Mill River and the carriage road. The railroad 
has made its own way by a cut through the western bluff. 

The gap, being thus a convenient place for an ice-dam during 
the melting of the glacier, one 45 feet high was then constructed. 
Ice-dams in spring from the melting of the winter ice are com- 
mon now-a-days and often make great floods ; but at that time 
there was not only an almost unlimited amount of ice, but also 
earth and stones in the ice to aid as packing. 

Mill River was then a great stream. It had, as part of its 
tributaries, the Farmington River from its source in the high 
region of Western Massachusetts to Tariff ville ; for an ice-dam 
at Tariffville cut off this river's head with the most of its length, 
and transferred the whole to Mill River. It received also the 
upper waters of the Quinnipiac, in consequence of a similar dam 
along the sandstone gorge between Cheshire and Meriden. Mill 
River had consequently a very large drainage area in the season 
of the flood. Part of the evidence with regard to the height of 
the dam at Mt. Carmel consists in the level of the water below 
Cheshire as indicated by the height of the terraces ; and part in 
the groovings and large excavations in the sandstone below the 
dam along the present course of the railroad at a considerable 
level above the bed of the present Mill River valley. The posi- 
tion of the railroad against the west side of the valley, and the 
form of the surface of the trap ridge west of the railroad-cut, 
show that the waters which made the grooves and trenches 
along the railroad were from the toest end of the dam. They 
were those of a literal sluice-way. 

The accompanying figure is a profile of the gap, with the 
height exaggerated only two times. It shows the position of 
Mill River ; of the carriage road at N ; and of the railroad cut 
at R ; and the form of the surface above the cut at HC. By 
ascending to the summit at HC, the height of the dam indi- 
5 



58 Walks and Drives about New Haven. 

cated by the dotted line will be appreciated, and the fact that 
the waters would have overflowed at H ; and there, at a height 
of 164 feet above tide level, began the sluice-way. Stratified 
gravel, deposited by the torrent under the lee of this ledge 
(visible from the railroad cut R) has a height of about 152 feet; 
and the upper limit now visible of the excavated trough or 
sluice-way near the Mt. Carmel railroad station, half a mile 
south of the gap, has a height of 145 feet. This trough or 
sluice-way in the sandstone was uncovered in grading for a new 
lay-out of the railroad, it offering the needed level for the track. 
It may be traced along the course of the railroad for 200 yards 
below the station ; it then passes to the westward of the road 
and becomes the head of a partly cobble-stone paved valley 
whose stream — which may be called Sluice-way Brook (Plate I), 
joins Mill River below Centerville. The first part of the course 



Profile of the Mt. Carmel village gap. R, railroad cut. 

is marked by multitudes of bowlders on the west side of the 
railroad below the cut, all of them beautifully smoothed, but 
not scratched, because of the scouring they had from the gravel- 
bearing waters. 

The junction of Sluice-way Brook and Mill River is shown with 
all the details here described in the Bache chart. Below Center- 
ville, where the stream left its own valley to join Mill River, its 
course is marked by great accumulations of stones, and also, by 
a large cluster of " Kettle-holes." The kettle-holes may be best 
seen by going across the region, along the road just south of 
Sluice-way Brook. It is a strange place. Some of the kettle 
holes have a depth of 40 feet and a marsh at bottom on a level 
with the river. None open into the river channel ; instead the 
margins of the kettle holes are 60 to 80 feet above the river. 



Walks and Drives about New Haven. 59 

Mill River valley bears evidence that the river was one of 
great magnitude and velocity in the beds of cobble-stone gravel 
to be seen along its course through Whitneyville. The cobble- 
stones which have been gathered on its western border on Orange 
Street for use in asphalt pavements are from deposits then made 
by the flooded river. 



10. To Meriden and the Hanging Hills. 

For an afternoon excursion to Meriden, distant 19 miles, the 
cars may be taken at twelve or one. The Hanging Hills are 10 
miles east-of-north of Mt. Carmel and 1^ to 2^ miles northwest 
of Meriden (see map, p. 44). They are trap mountains, remark- 
able for their steep declivities and high precipitous brows, 
which give to the observer beneath them an impression of over- 
hanging, and hence the name. Three "Hills" stand together on 
a common line, West Mountain, South Mountain, and Cat Hole 
Mountain. West Mountain has three summits, an eastern, a 
middle, and a western, separated from one another by a cut 
down to the lower limit of the mural rocks. The western of the 
three peaks is the highest ; Prof. Guyot made it 995 feet above 
the sea. 

To reach West Mountain from Meriden go westward along 
Main street, and its continuation the Waterbury turnpike (pass- 
ing Fenn's millpond north of the road two-thirds of a mile on, 
and, immediately afterward, crossing a road that leads northward 
to Cat Hole gap and Kensington) ; at the forking, \\ m. out, 
keep to the right, taking what is called the Southington road, 
and continue on it about 1^ m. farther (passing, half way, a road 
going north to the " Notch " between South Mountain and West 
Mountain); and when seemingly a little beyond the sought-for 
mountain, and just after a descent begins in the road, a carriage- 
path will be seen on the right (north) entering the woods, 
showing by its stripes of green that it is not much used ; after 
half a mile or more upon this path, gradually ascending most of 
the way, an open spot is reached where the carriage way ends 
and the climb begins. 

Along the road thus far glimpses are had of Meriden, and the 
eastern hills, of Mt. Carmel to the south, and finally of the 



60 Walks and Drives about New Haven. 

Cheshire and Southington region and the heights to the west. 
A prettily wooded bank with a streamlet at its jjpot follows part 
of the way the south side of the Southington road. After 
passing two or three millponds to the north of the road, another, 
large enough to be called a lake, and none the less beautiful that 
it is artificial, is seen lying among the forests. Nearly all the 
way the Hanging Hills are in full sight, grand in all their vary- 
ing aspects. In many places along the mural fronts great 
columnar masses stand out, clinging only by a single side, owing 
to the fall of the rocks underneath, and appearing as if just 
ready to go crashing down the mountain. But they hold on 
firmly, for the work of destruction in these trappean structures is 
slow. The long slope which rises at a large angle to hundreds 
of feet, and bears far aloft the grand lines of battlements, is, to a 
great depth, made of the stones that have fallen from the 
heights. 

A path leads up to the summit. The first part of the summit 
which comes into view is made up, at its lower portion in front, 
of small columns, hardly longer or larger than a man's leg, that 
are gradually falling apart and adding thus to the debris. This 
small-columnar structure characterizes many parts of the Meriden 
Hills, and, as a consequence, the long slopes of fallen fragments 
often consist of such pieces of rock — some flat, but generally 
of irregularly polygonal shapes. Nowhere about the Meriden 
heights are large regular columns to be seen. This seems 
remarkable, considering the extent of the trap eruptions. Much 
of the trap breaks with broad vertical surfaces like Pine Rock 
and West Rock, and somewhat less plainly, East Rock. Just 
above the point referred to, and farther on along the gorge, the 
trap stands up in long perpendicular walls arising from vertical 
courses of fracture. The immense blocks of trap that roughly 
pave the bottom of the gorge remind one who is familiar with 
the New Haven region of the great trap bowlders on its western 
hills. They have the same fine-grained texture, and are often 
tabular in form, and laminated in structure. 

The rock of the summit is fine-grained trap, or the crust rock, 
as it is well called, like that of the great bowlders of the New 
Haven region ; but below, as may be observed on the way up, 
it is coarse in grain like the Easl Rock stone. (The crust rock 



Walks and Drives about New Haven. 61 

is not so named because separable from that below, but from its 
being the original exterior of the ejected trap, as proved by its 
fine texture.) The presence of the crnst-rock at the top shows 
that but little of the height of the ridge was worn away by the 
old glacier as.it moved over these summits. In fact, nothing 
else could be expected ; for along this meridian there were 
probably few stones in the ice at a level high enough to over-ride 
or abrade the summit. There are no peaks in the valley to the 
north as high as this Meriden mountain, either in Connecticut or 
Massachusetts, except Mount Tom and Mt. Holyoke ; and stones 
taken from lower heights would not have risen in the glacier 
against gravity to a higher level, except through a combination 
of circumstances in the slopes that should favor an up-hill push 
of the ice ; and the circumstances about this West mountain do 
not appear to have been favorable for an upward movement of 
this kind. The Mount Tom bowlders would have made a nar- 
row line, and would have had but little chance of leaving their 
mark, or much of their freight, on this high Meriden Station. 

Over the bare trap surface of the summit, there are slightly 
raised lines dividing it into polygonal areas, which indicate 
that the rock beneath has a somewhat columnar structure. These 
lines are prominent because of the greater hardness of the rock 
along them, the intervening surface yielding most easily to the 
elements. This hardness is due to the filling of thin fissures with 
silica or some siliceous mineral ; and the fissures were a result 
of the contraction of the rock at the time of its original cooling. 

The long lines of fracture or open seams which intersect the 
surface are the courses of the joints, on which the laminated 
character of the rock (or its tendency to break into slabs and 
tabular masses) depends. 

The view from the top of West Mountain is remarkable rather 
for its wide panoramic range than for grandeur of detail. In the 
landscape a wide undulating surface, seemingly almost a level 
plain, stretches from Berlin and Meriden, southward over Wall- 
ingford and North Haven, westward over Cheshire, and thence 
northward over Southington into Bristol ; and the villages of 
these townships lie among great patches of forests, meadows and 
variously cultivated fields. On the east stands the long range of 
trap ridges from Mount Lamentation to Saltonstall Ridge in East 



62 Walks and Drives about New Haven. 

Haven. Farther south, are seen the Sound, and Long Island. 
More to the west, are Mount Carmel, 936 feet above tide level 
and over its flank, a part of the East Rock range, a spire in Fair 
Haven, and the old Light House on New Haven Bay. 

To the southwestward, the northern part of the long West 
Rock range stretches on between Cheshire and Prospect, then 
bends a little eastward, and soon after loses itself in the open 
country of southern Southington, west of the Meriden Heights ; 
for here the range terminates, about 17 miles from its commence- 
ment at Westville. Over and beyond these trap hills to the 
west, and also to the northwest, lies the elevated Woodbridge 
plateau, a region of crystalline or metamorphic rocks, attaining 
its greatest altitude in the towns of Prospect and Wolcott, and 
thence, declining toward Bristol. Still farther northwest, over 
Wolcott and Bristol, there are the heights beyond the Nauga- 
tuck, and the more remote and but faintly discerned Taconic 
Mountains of the Green Mountain Range. Among the summits 
on the western horizon, one quite prominent, called Great Moun- 
tain, belongs to the countiy beyond the Housatonic not far from 
the State boundary — Mt. Washington. 

Turning to the northward, other trap hills come into view in a 
long range, terminating in Mt. Tom and Mt. Holyoke. The 
nearer, with rampant western front, are the hills overlooking 
Southington and Farmington ; farther on is Talcott Mountain, 
on the western border of the town of Hartford. The ridges of 
Simsbury and Granby rise beyond, but they are not separately 
distinguishable* as they are seen only in profile. Mt. Tom shows 
itself, over what appears to be a low western extension of 
Talcott mountain, as a round-topped peak, steepest on its western 
side. To the right is Mt. Holyoke, (on the other side of the 
Connecticut) ; and still farther east are other summits of the 
Holyoke ridge. It is of interest here to remember what has 
been already stated, that these trap hills make one grand curving 
range, nearly 60 miles long, from West Mountain in Meriden to 
Mount Tom, and thence, bending easterly, to Mount Holyoke. 

Many villages give life to the landscape. North of Meriden 
there are Berlin bearing northeast, New Britain north-northeast, 
Kensington, Percival's birth-place, south of New Britain, N. 30° 
E. ; south of Meriden, Hanover or South Meriden, near a large 



Walks and Drives about New Haven. 63 

pond at the bend in the Quinnipiac, bearing S. 15° E. ; Yalesville, 
more distant, in nearly the same direction, and beyond Yalesville, 
the much larger village of Wallingford ; in the valley to the 
west, Bristol, bearing N. 52° W., Southington, N. 30° W., 
Cheshire, S. 30° W. ; oyer the Woodbridge plateau, Wolcott N. 
58° W., and Prospect, on the summit against the horizon, S. 60° W. 

Crossing the summit eastward, a good walker may descend the 
long and steep slope of trap debris into the Reservoir gorge. For 
the drive it is necessary to go around by the road. The Reservoir 
is really a lake ; and lying amid forest-covered slopes in this 
mountain defile, overlooked by and reflecting the grand old walls 
that crown the heights, it is a scene of beauty seldom surpassed. 

From the entrance to the gorge a path leads by the foot of the 
Hanging Hills westward to the Cold Spring gorge, near the 
Poorhouse. This spot is remarkable for the great bowlders 
which here lie piled together ; and also for the cold water that 
comes up from a deep recess between the huge masses of trap, in 
which ice usually keeps the year around, the shade and shelter 
making the spot a natural ice-house. Professor Silliman gives one 
of the earliest published accounts of the place in vol. iv, page 17, 
of the American Journal of Science, after a visit on July 23d. 
1821. He carried off with him to New Haven a mass of the ice 
weighing several pounds. 

The grand pile of rocks at the bottom derived from the 
heights above, the long steep slope of fallen fragments down 
which they made their descent, and the mural heights almost 
overhead seemingly ready for other avalanches, produce an im- 
pression of power and sublimity that is seldom an effect of 
simply motionless rocks. But here every object in the scene 
suggests motion and violence. Yet the blocks, gray and green 
with the vegetation over them, look as if they had lain quietly 
in their places for ages. The work of destruction above is, 
however, going slowly forward, and though a long period may 
intervene, other descents are sure to occur. A long, one-storied 
stone house stands just within the entrance of the gorge, which 
is made of thin columnar pieces of trap three to four feet 
long, so laid that the ends project very unequally. The queer 
porcupine-structure was erected for a ten-pin alley, as an append- 
age to the " Cold Spring House " (a Water-Cure establishment 



64 Walks and Drives about New Haven. 

that formerly occupied what is now the Poorhouse). If it does 
not, in the mean time, go to pieces by natural decay, it may 
yet feel the weight of one of the descending 1000-ton masses. 
Should this happen, a strike would be made beyond any former 
experience of the ten-pin alley. The place also has its shady 
ways and rock retreats, beautiful with their moss-covered walls, 
shelves of ferns or flowers, and over-shadowing trees, which may 
give much enjoyment in the exploration. 

The trap on the east side of the gorge near the path (and in 
many other places about the base of the mountains) is for the 
most part amygdaloidal ; and below the rusty, decomposed, 
crumbling exterior, the cavities contain commonly calcite, some- 
times crystallized quartz, and now and then amethyst and agate. 

The distance back to the Meriden railroad station from this 
place is about 2 miles ; from the reservoir in the notch 3 miles ; 
and from the place of ascent of West .Mountain, a little over 3^ 
miles.- This is one of several interesting excursions that might 
be made about Meriden. 

About the mill pond to the southwest of Meriden abundant 
evidence will be found of the feebleness of the Quinnipiac River 
at the time of the glacial flood. The low terrace is hardly a fifth 
of that at Cheshire. The deposits are sand and fine gravel, not 
coarse gravel and stones. The desert-like sandy surface between 
Wallingford and North Haven is a consequence of the compara- 
tive feebleness of the stream. 



11. To Roaring Brook — A Drive or a Long Walk. 

Roaring Brook flows in a deep gorge in the West Rock Ridge 
about 11^ miles north of New Haven, but by the road about 14 
miles. It is 2^ miles from the Cheshire station on the Canal 
railroad, and 1^ miles from Brooks' Station. The latter is not a 
station now unless the party to the gorge is large. To find the 
gorge from Brooks' Station, follow the road that leads west and 
then north for nearly \\ m. to a point where it crosses a brook, 
and where another road commences on the right by crossing the 
same brook ; here turn and continue on for half a mile to bars, 



Walks and Drives about New Haven. 65 

beyond which is a wagon path. This path leads directly to the 
gorge, passing a saw-mill on the way. Farther to the right 
(north) there is a deep notch in the trap ridge, but the notch of 
the brook is a comparatively slight one. 

The gorge is a deep cut into the heart of the mountain. At 
the principal fall, about half a mile up, the water descends about 
60 feet in three falls, half of it in the first, and when the stream 
is full it is all one cascade. But a mill pond above uses up much 
of the water and now it seldom roars. There is much to enjoy 
in the way of scenery along the gorge ; and by climbing the 
summit to the south, covered with pines, a fine distant view is to 
be had. It will also be observed from the summit that there is 
no valley like that of West River between the trap range and 
the region of crystalline rocks of the town of Prospect on the 
west. The Arbutus grows abundantly along the way. In the 
bottom of the goi'ge at a spot nearly up to the falls the mineral 
datolite has been obtained in fine crystallizations by blasting into 
a vein. 



12. To West Rock and the Judges' Cave — A Walk or 

Drive. 

The best route to West Rock is by Whalley Avenue and Blake 
Street, or by Goffe and Blake Streets, to the east point of the 
Rock ; thence westward to the low extension of the trap ridge 
which makes the head of the first quarry, on the west side of 
which the path commences. The place may be reached from 
Westville by Pearl Street (the first west of the Post Office) and, 
after crossing the bridge, the third street going north; or else, if 
on foot, the first to the foot of the slope, and then following the 
path along the foot of the slope eastward. The ridge along 
which the ascent is made has been much narrowed by quarrying, 
but there is still little difficulty in following it to the summit. 

On the ascent, at a height between 300 and 310 feet, going 
eastward a short distance, there is a fine view to the east and 
south ; the Triangle and the bare wall of trap facing it are in the 
foreground. 



66 Walks a?id Drives about Ne%o Ilaven. 

The summit surveying station has a height on the Bache map 
of 399 feet.* In the fine view southward the West River valley 
— which is tidal to Westville — is a prominent feature ; but it has 
lost some of its charm now that the meandering stream has been 
turned into a straight canal for the benefit of the grass of the 
meadows. 

A path goes along the top of the Rock westward, and by it 
the Judges' Cave may be reached in 12 to 1.5 minutes — the dis- 
tance being about 1000 yards. The great masses of trap which 
lie together and make all there is of a cave, were probably united 
when the bowlder left the glacier. The breaking has come 
mainly from the growth of trees. The position is a little below 
the top of the ridge ; and it is thereby evident that the journey- 
ing bowlder was at too low a level in the glacier to clear the 
summit. Were it not for this, it might have been carried on to 
join the large bowlders on the grounds of Donald (4. Mitchell. 
The rock is fine-grained and much rifted, quite unlike that of the 
trap surface beneath it, and like the crust-rock of the Meriden 
Hills. 

The cave is a poor place for shelter. But here at intervals in 
the summer of 1661 two officers of the Cromwellian army, raem- 
bers of Parliament and signers of the death-warrant of King 
Charles I, found shelter and protection from the royal pursuers 
who came in search of them soon after the Restoration. These 
refugees, familiarly known to the colonists of their time as "the 
Colonels," were Edward Whalley, and his son-in-law, William 
Goffe. Whalley died at Hadley, Mass., about ItiTS, and Goffe 
at either Hartford or New Haven, in 1680. Colonel John Dix- 
well, another of the so-called "regicides," came to New Haven 
about 167o, and died there in 1689. His monument stands on 
the public square behind the Center Church. 

The descent, from the cave may be made along a path leading 
down eastward to a short east-and-west road, and thence into the 

* Prof. W. H. Brewer made the first barometric measurement of West Rock, 
November 13, 1866. He found the height of the summit near the front 393 feet, 
and a spot a little farther north a few feet higher. In making this measure- 
ment. Prof. Brewer had the misfortune to break his barometer — one that he had 
carried for years without accident over the peaks of the Sierra Nevada in Cali- 
fornia, 12,000 feet and more in height. The next year after this mishap a 
quicksilver mine was discovered on West Rock ! 



Walks and Drives about New Haven. 67 

main road at the east foot of the Rock, and joining the latter at 
a point near a bridge over Wilrnot Brook. The route across the 
bridge is the shortest way to the city. 

On the way down from the cave, large masses of the granite- 
like rock, gneiss, may be observed. Many such occur along the 
eastern slope of West Rock Ridge, and all came from the Nauga- 
tuck Valley or beyond, as ah'eady explained. 

West Rock may also be ascended by the path, jnst mentioned, 
to the Judges' Cave ; and, for wheels, a carriage road to the 
Cave from the vicinity of the Almshouse, has been begun. 

Another good route is by the path from the eastern foot of the 
ridge, just north of the Triangle. On Plate VI two paths ascend 
together ; the north one has been made under the direction of 
the Park Commissioners, the commencement of a wide walk to 
the Judges' Cave. Just north of its commencement " Wet Run " 
descends, and a good drink of water may be obtained at the road- 
side. It is a wet run because the bed is in sandstone. To the 
south is " Dry Run," a good bed for a stream, but usually dry, 
because it is of trap, a rock abounding in fissures. If the purpose 
is to go directly to the summit of the Rock, and not to the 
Judges' Cave, keep on the old path as far as it is distinct, and 
then go directly west. Above a level of 300 feet the surface is 
of trap ; but the slopes are easy of ascent to the path near the 
western brow. 



13. To the South Front of West Rock and the Judges' 
Notch — A Walk, and for part of the way a Drive. 

The south front of West Rock, a portion of which is repre- 
sented on Plate VII, is visible in part from the road before 
arriving at Westville, but best in Westville from the top of the 
terrace at the north end of the street (Franklin St.) just west of 
the Westville School House. The cars pass the street, and 
wheels may go to the spot. When taking the view, it must be 
in mind that the trap came up melted along a line to the east- 
ward, and flowed westward over the ledges of upturned sand- 
stone (p. 30). 

To reach the quarry road at the foot of the section, which is 
90 to 100 feet above tide-level, cross West River by the Pearl 



6S Walks and Drives about New Haven. 

St. bridge, take the first left hand road to the foot of the moun- 
tain, then go eastward to a small shed, whence a path leads up to 
the road. First see a piece of the evidence that the trap came 
up to the eastward in a large outcrop just north of the "shed" 
at the foot of the mountain ; it is nearly 60 feet below the level 
of the outcrop of sandstone beneath trap on the road above. The 
quarry road is easily reached by wheels, by continuing on Pearl 
Street to the third road going north. 

The absence of distinct columns in the precipitous front is a 
point to be observed ; and, instead, very distinct planes of divis- 
ion or joints in the trap conforming in direction to the face of 
the Rock, though with considerable variation ; and also another 
less prominent transverse system of joints. The direction of 
the face-joints is about N. 80° W., becoming N. 70° W. farther 
west ; and their northward inclination is 15° to 18°. Further, 
there is a remarkable twist in the face-joints over the eastward- 
dipping sandstone, they veering around so as to have the 
direction very nearly of the strike of the sandstone between N. 
and N. 10° W. ; the more prominent joints thus changing places 
with the transverse. 

The outcrops of the sandstone farther west have been enlarged 
somewhat since the photograph of Plate VII was taken. It will 
be seen that the crumbling purplish layer becomes darker above ; 
and that portions of a red layer at bottom are in sight. The 
junction line of the trap and sandstone is in most parts accessi- 
ble to an enterprising climber. The quarry road continues for 
200 yards beyond the part represented in Plate VII, and other 
outcrops of sandstone come successively into view. 

On page 31 the conclusion is drawn that the outflow of trap 
was a flow under a cover of sandstone and not an outside flow. 
But the point should have further investigation. If on the exam- 
ination of the junction-plane of the trap and sandstone here and 
elsewhere in the Connecticut valley there should be found between 
them a bed of earth, gravel, or stones not of possible derivation 
from the trap or sandstone, or relics of terrestrial life of any 
kind, or any water channels or other evidences that the surface 
of the sandstone had been a region open to the air, the evidence 
would be adverse to the conclusion. On the contrary, it would 
be favorable to it if only angular fragments of sandstone, which 



Walks and Drives about New Haven. 69 

the onward shove of the flowing lava might make, are found, or 
rounded masses of sandstone or trap, isolated or in beds, such as 
might be formed underneath the heavily flowing mass. 

In order to reach the Judges' Notch from the end of the 
quarry road, descend to the road of the valley ; or if the bank of 
the river is reached, continue on it northward to the road and a 
bridge ; then follow the road northward to the first white house, 
and there take the path northeastward through the partly shaded 
fields to the Judges' Notch. An eastward path goes off up the 
notch soon after passing the dry (or wet) bed of a brook. On 
the ascent, coarse sandstone may be observed a short distance 
below the trap. On arriving at the summit, which is about 360 
feet high, the Judges' Cave will be found a short distance to 
the southeast. 

From the cave the descent may be that of the preceding excur- 
sion. But an interesting and untrodden route is as followB : 
To the surveying station at 399; thence down to 300, at the head 
of the Triangle ; here northward to the top of the bare wall of 
trap facing the Triangle, and into the trough adjoining. (Plate 
VI). This route ends in the Triangle behind the second house. 



14. TO WiNTERGREEN LAKE A WALK OR DRIVE. 

The road passing the east point of West Rock continues on 
beyond the Almshouse, going by its west side, and nearly a 
mile north reaches the foot of the little trap ridge which bounds 
Wintergreen Lake on its south side, and also the border of a small 
flow of water which has served at many picnics. A path ascends 
the ridge to the lake. 

The carriage road turns eastward and makes a rather steep 
ascent out of the valley, and affords one way of returning to 
town. After making this ascent the pedestrian may take the 
road near by going directly east, and thus make his way toward 
Dixwell Avenue and the city. But this road is a steep one for 
w r heels ; the one next north is much better. 

A more interesting i-oute home for the pedesti'ian is through 
the woods up West Rock Ridge to Wintergreen Notch, and 
thence down to West River valley and Westville. There is a 
fine exhibition of trap columns north of the path on the descent. 



TO Walks and Drives about New Haven. 

The trap along the south side of Wintergreeo Lake is the 
eastern extremity of the "Buttress dike." It differs from the 
trap of West Rock in containing whitish spots every 3 or 4 
inches, which are due to imbedded crystals of the feldspar 
anorthite ; and with a hammer in hand this porphyritic character 
may be used for tracing the dike across the West Rock Ridge. 



15. To the Buttress Dike — A Walk. 

Buttress dike is the only one of the kind yet known in the 
Connecticut valley, that is, the only one that cuts through one of 
the large trap ridges and thus shows that it was ejected after the 
trap it intersects had cooled. It has therefore special geological 
interest. Besides this, there are pleasurable difficulties and risks 
in the ascent. Moreover, it affords on the way up gradually 
changing views of the whole West River valley from far north 
to the Sound, which increase in interest with each new stage of 
elevation ; and when Buttress Peak is finally reached, the addi- 
tion to the view, at last, of the New Haven plain, with West 
Rock to the south in the foreground, is a surprise that adds 
much to the gratification. 

At Westville, take the road up West River valley and con- 
tinue on it beyond the Pond Lily Paper Mill. A bridge not far 
on affords a chance to cross the river on the way either to 
Wintergreen Notch, or to the Buttress dike which is not far north 
of the road to the notch. There is also a bridge across the river 
nearly in a line with the dike. The Buttress projects from the 
steep front of West Rock, and, before the leaving out in spring, 
is visible from the road. Later it is a mass of foliage to the 
bottom, between slopes of West Rock debris. It consists of 
solid columnar trap ; and the columns, as may be seen on the 
ascent, have a pitch southward. Two-thirds of the way up, 
there is a chance to go along the northern wall of the dike to 
the place where it cuts through the West Rock trap, and with a 
hammer to observe the difference between the rocks of the two. 
From this point the adventurous climber may make his way in a 
corner up the steep front to the summit, while the more prudent 
will return to the dike and follow its roucrh course. At the 



Walks and Drives about New Haven. 71 

summit the dike is traceable only by means of a hammer ; but 
farther down the eastern slope it stands above the surface as a 
bold ridge ; and from there it may be easily followed to the 
southern border of Wintergreen Lake. 

A plotting of the route followed along the dike from West 
River valley over the summit to the lake would show a very 
large bend in the course of the dike. But this bend in a plotting 
is owing to the inclination of the dike southward of about 25° 
and to the height of the Rock, about 450 feet, or 350 above the 
West River plain at the western base ; this height and angle giv- 
ing the dike at the summit a southward throw of more than 150 
feet. Shaved off to a level plane the actual course of the dike 
would be found to be straight, and about N. 35° E. 

Continuing along the border of the lake on the dike, its end is 
reached in about 300 yards. Here the dam is in sight to which 
the lake owes its existence. 

To find Wintergreen Gorge and Falls, go southward by the 
road for about 500 yards ; then turn eastward to a branch of 
Wilmot Brook, the stream that flows from the lake ; and in the 
course of a few rods the gorge and falls will be reached. It was 
a place of much beauty before the lake used up the water ; and 
it is so now after heavy rains. The best point of view is from a 
high rock, at the summit of the gorge, below the falls, some dis- 
tance east of a dwelling house. 



16. Through Western Hamden, the southern Bethany 

Notch in West Rock Ridge and West River 

Valley — A Drive or a Long Walk. 

This highly interesting drive passes in sight of West Rock on 
its eastern or more sloping side, crosses the narrow notch (w 3 , 
Plate I) westward, and then returns in West River valley along 
the western or palisade side of the ridge. The best route for fine 
views is by Dixwell Avenue to Arch Street (2 m.) ; along Arch 
Street across the northeast end of the Beaver Pond Meadows, 
and then bending northward, passing between the main body of 
Pine Rock (C C, Plate I) and the eastern outlier (D) ; and 
thence northward to the second road crossing ; here turn north- 



72 Walks and Drives about New Haven. 

westward and keep on westward to the road nearest the foot of 
West Rock Ridge and follow this road to the Notch. The 
height of the Notch hefore beginning the descent (according to 
the Bache map) is 500 feet, and of West Rock in the vicinity, 
650 to 700 feet. Passing the Notch, the route is a nearly 
straight one down the valley to Westville. Before passing the 
Notch tlic ascent of a high trap peak — Wn, Plate I (called 
Warner's Rock, height 610, Bache) will have its reward in a 
grand view southward and southeastward. 

The distance from New Haven is 3 m. to the Pine Rock gap ; 
and, including this, 8 m. to the Notch ; thence southward 7 m. 
to Westville. 



17. To Sargent's River, the Cement-works, and Wood- 
bridge — A Walk or Drive. 

Sargent's River is about 4 miles from Westville. There are 
tine views of the West Rock palisades all along the way ; and 
nearing Sargent's River, the large lake, made for water-supply 
to the city, adds to the beauty of the region. The rock passed 
on the latter part of the way is a poor variety of rooting slate, 
called in geology hydromica schist. The slate stands at a high 
angle, and at places contains quartz veins. 

The lime-kiln of the cement-works is in full view at Sargent's 
River. A path leads to the quarry from which the limestone for 
burning was obtained. The limestone in the quarry stands at a 
high angle between layers of the hydromica schist, The most of 
it contains minute, brilliant cubes of pyrite, and is also impure 
from the presence of much mica in fine scales. Owing to the 
pyrite (a compound of iron and sulphur) the limestone decom- 
poses very easily, Leaving behind a thick, dark brown, earthy 
crust resulting from the decomposition of the mica with some of 
the hydrous iron oxide, limonite, due to the oxidation of the iron 
in the pyrite. 

A true cement-rock is a limestone impure from the presence of 
clay. An analysis proved that the chemical constitution was 
essentially that of a good cement-rock. But it turned out, after 
much momy had been spent, that, inasmuch as the impurity was 



Walks and Drives about New Haven. 73 

mica, the limestone ran into a slag instead of burning properly 
to lime; and then, after meeting this difficulty by using less heat, 
that the lime obtained was good for nothing for making cement 
(a mortar that will set under water). 

The road going west by the north side of Sargent's River 
passes through Sargent's Glen. The drive south through Wood- 
bridge is very enjoyable on account of its fine views. 

On the return, the rock along the way will be found to be the 
slate, hydromica schist, until a cross-road is reached, near a small 
factory, about three-fourths of a mile from the junction with the 
valley road. At this point the hydromica schist is the rock of 
the hills some distance west of the road ; but the road there is a 
greenish rock, called — from the greenish mineral, chlorite, which 
it contains, chloritic hydromica schist. This greenish rock con- 
tinues southward all the way to Savin Rock. At this place 
in West River valley it narrows out and disappears beneath 
the alluvium of the valley, heading obliquely toward the West 
Rock ridge. It is a western portion of a small anticline, having 
N. 38° E. as its direction or strike. 



18. By West River Valley to the Second Bethany 

Notch and back by the "West Woods Road" 

through Hamden — A Drive. 

Take the road up West River valley to the southern Bethany 
Notch (n 3 , Plate I) ; but instead of crossing at this notch, 
continue northward half a mile to the next notch (n 2 ), which 
has scenery to enjoy. Here go eastward first by the south side of 
a brook ; then turning northward where a road comes in, cross 
the brook ; then take the first road to the right or eastward and 
again cross the brook just after passing a road going north ; 
thence eastward to the second road going south, which is the 
West Woods road ; the distance from the Notch is nearly 2 
miles. The northern part of this drive is through forests — a 
wild woods drive. In 3 miles the road joins Dixwell Avenue by 
the side of Sluiceway Brook in the vicinity of Augurville, 1\ 
miles north of Whitneyville. The whole distance around from 
New Haven is about 20 miles. 
6 



74 Walks and Drives about New Haven. 



19. WOODBRIDGE HEIGHTS AND THE GREAT BoWLDEE A 

Walk ok Drive. 

Reaching Westville go west on Fountain Street. The first 
rise in the road is to the top of the West River terrace — the 
western part of the New Haven plain, which is about 60 feet 
above the level of the river. The gravel which underlies it is 
largely of the cobblestone kind ; for the glacial flood came down 
West River valley with great violence, making a fall of 80 feet 
a mile from Bethany. By the Westville cars this ascent is made 
on Main Street, and then by a cross street, Fountain Street is 
reached. Soon the street takes another rise — that over the low 
northern part of the Edgewood Ridge — a ridge on which "Edge- 
wood," the estate of Donald Mitchell, is situated. The road next 
crosses the broad Maltby Park valley, so named from Maltby 
Park, which lies in it a mile to the south. A lake occupies the 
breadth of the valley 150 yards to the north of the road ; but 
o-reat ice-houses injure the view. A little over a mile from West- 
ville the ascent of the " long hill " or the Woodbridge Heights 
commences and while on the way up, the following explanations 
are in place. 

Maltby Park valley and its bordering ridges make the western 
border of the New Haven region from here southward to Savin 
Rock on the Sound, and have a common geological history. The 
valley and Edgewood Ridge disappear, half a mile to the north, 
in West River valley. Two miles north the ridge of Wood- 
bridge Heights also ends in the valley ; its course is here 
N. 38° E., while that of the adjoining part of the valley and of 
West Rock Ridge is nearly north and south. Southward Maltby 
Park valley becomes the valley of Cove River, which enters the 
Sound a mile west of Savin Rock. 

Geologically, the valley and the confining ridges are the course 
of a great upward bend in the rocks, or an anticline, a result of a 
mountain-making movement in Paleozoic time or earlier ; and 
thus it is that they have a common origin. Like most anticlines 
the stretching of the rocks in the bending occasioned large and 
deep fractures along the summit of the arch, and this led to de- 
gradation through the waters of the sea and rivers, producing 
the valley and its many ledges. 



Walks and Drives about New Haven. 75 

The summit of the " long hill " is reached on passing the Clin- 
ton cottage. North of the road, 140 yards below the cottage, a 
path goes from the road northward ; and within 100 yards a 
high summit west of it affords a fine view, in which West Rock 
is projected on East Rock. Just west of the Clinton cottage a 
high crag of abrupt sides overlooks the leafy Maltby Park valley 
with its lake, the Edgewood Ridge, and beyond these the city and 
country over a wide range ; but the view, a few years since one 
of the best in the whole circuit of New Haven, is now obstructed 
by a new gi'owth of trees ; and another cutting of the forest 
must be waited for before the Clinton Crag will repay for the 
climb. On the same line half a mile south another high crag has 
afforded a similar view still more panoramic. A wagon-path, 
starting just below the cottage, leads southward to the ledge. 
(In following it be careful, when nearly half way, not to turn off 
by a branch path to the westward.) 

The high points along the crest of the eastern Woodbridge 
Ridge are good places for a geological thought — that during the 
Jura-Trias period, when the Red Sandstone was forming in the 
wide Connecticut valley estuary (see page 00), this Woodbridge 
region was a part of the western shore of the estuary. The rock 
of the region is the chloritic hydromica schist, already men- 
tioned. It here stands nearly vertical, the dip of the beds being 
westward 70° to 80° and 90°. 

One hundred yards west of the Clinton cottage, north of the 
road, the Buttress trap-dike rises above the surface with a vertical 
eastern front — being thus prominent because more enduring than 
the slates either side. A hard blow with a hammer will suffice to 
obtain evidence that the rock is not the slate or schist, but true 
trap, much like that of West Rock. There are good views to be 
had from the top of the dike. But the best, and one especially 
charming, requires a walk in the direction of the dike eastward 
(N. 35° E.) to its highest point (about half a mile from the road) 
where it overlooks West River valley. It adds this valley to the 
New Haven prospect and includes a near view of West Rock ; 
and through Wintergreen Notch appears, in the distance, Tremont, 
of the Durham trap ridges. There is a difficulty in the walk ; for 
the dike in places disappears beneath the surface. The best 
route to the lookout is by the path going northward and east- 



76 Walks and Drives about New Haven. 

ward, 140 yards below the Clinton cottage ; it leaves the road 
near a tub for watering horses. The path, where obscure, is 
marked by red tags ; it leads directly to the extremity of the 
dike overlooking West River valley — 360 feet above high tide 
according to the Bache chart. 

When there, the great 1200-ton bowlder is only 200 yards off 
to the west of south. From the south side of the dike a line 
of red tags indicates the way. The region has recently become 
so overgrown that the great mass is visible but a few yards off, 
and the extended view from its top is narrowed to a mere cleft 
between the tree tops. 

The trap-dike may be followed by taking one of the paths east 
of it ; but they cross its course, and there is a risk of losing the 
way. A hammer may be needed to re-discover the dike. 

Till recently a growing cedar had its roots in a cleft in the 
upper surface of the bowlder, threatening to break it in two. 
But a ring of the bark was taken out from the base of the trunk, 
and now, although the cedar still stands, it is dry, and the bowl- 
der is safe from the disaster. 

From here the way may be retraced to the road, and the drive 
or walk continued westward and, then hy the first road northward, 
eastward and southward through Woodbridge to the West River 
valley and Westville — the distance around 4f miles. Or the re- 
turn may be made by the pedestrian from the bowlder northward 
to the dike ; thence across it, and north east wai'd to the east slope 
of the hill into the valley. 

At the commencement of the descent there is a large bowlder 
of trap in two pieces, and a look off may be had from its top. 
Three others lie near by now concealed by the trees and shrubbery. 
Going northward an open field is reached, and over it the descent 
may be continued to the road at its foot. The great bowlders 
are lodged along these heights, about one mile (5000 to 5400 feet) 
west of that of the Judges' Cave, because, like that, combed out 
of the ice by the ledges of the summit. 

Nearly a mile west of the Clinton cottage the road forks, one 
road going southwest to Derby and the other northwest to Sey- 
mour. At the forking the outcropping rock is that of the west- 
ern margin of the chloritic hydromica schist ; but along the west 
side of the outcrop a thin portion of the next rock in the series is 



Walks and Drives about New Haven. 77 

exposed to view, the hydrorrhea schist ; and here the boundary 
line passes between the two rocks. The chloritic schist contains 
epidote in some of its quartz seams. 

From the point in the road reached in the descent above de- 
scribed, it is but a short distance north to the small old factory 
referred to at the close of Excursion 17, where the chloritic schist 
makes its disappearance. This place (about \\ miles from West- 
ville) merits a careful examination in order to understand the fact 
there stated that the schist lies in an anticline ; and the hill to 
the west should be ascended to ascertain that the next rock west 
is the hydromica schist. This being proved, another location of 
the boundary between the two rocks has been approximately 
ascertained ; and others between the two are easily added. 



20. The Edgewood Walk or Drive. 

From Westville go out Fountain Street half a mile and then 
turn southward down Forest Street. It passes the residence of 
Donald G. Mitchell, which will be recognized by the long line of 
evergreen hedse in front of it. The road rises above the foot of 
the western hills — the Edgewood Ridge — and affords many tine 
views to the eastward. Chapel Street terminates in Forest Street 
about a fourth of a mile from Derby Avenue. Abreast of its 
termination three large trap bowlders, one of them weighing at 
least 250 tons, may be seen by crossing the fence and going on 
southwestward for a few rods. 

Forest Street crosses Derby Avenue, but to the south it is 
called Campbell Avenue. The drive may be continued south- 
ward along Campbell Avenue, which is much of the way shaded 
by trees, to Allingtown, and a return made by the Milford turn- 
pike. The distance from Fountain Street to Derby Avenue is a 
little over a mile ; to Allingtown, nearly 2 miles. If Derby 
Avenue is taken, the Yale Athletic Grounds, half a mile east, 
will be passed, and then a descent made to the level of the West 
River meadows and bridge. When passing the bridge it may be 
observed that each side of the river has its high terrace, and 
both at the same level, the terrace being that of the New Haven 
plain. The terraces have a height of 49 feet above mean tide. 
The position and height of the terrace-slopes along the river 
are shown on Plate I. 



78 Walks and Drives about New Haven. 



21. To Maltby Park — A Walk, oe in part a Drive. 

Out Chapel Street and Derby Avenue, passing West River, 
the Yale Athletic Grounds, and finally Forest Street. By the 
west side of this street is the summit of the Edgewood Ridge, 
the eastern boundary of Maltby Park valley, and a mile west 
are the Woodbridge Heights, its western boundary. Over the 
Park there are three lakes, a southeastern, northern and western, 
the first and third near the Derby road, and the other north of 
the first. These lakes were formed, under the-dh'ection and out- 
lay of Mr. C. S. Maltby, who embraced in his project four other 
lakes that were never constructed. He had in view, besides 
the laying out of a park, the supply of the city with water. 
Toward the former purpose good roads were laid out in different 
directions which at several points led to high summits and ex- 
tensive prospects. The Park grounds were offered to the City 
under certain restrictions, which were not accepted. Since then 
the New Haven Water Company has bought in the lakes. The 
roads, consequently, have been partly broken up and the summits 
overgrown, so that only pedestrians can enjoy it. Previous to 
the making of the lakes, the region was one of rocky ledges 
with small intervening valleys, forest-covered, and often marshy, 
and also of a quarry of serpentine-marble, which is now, to the 
misfortune of the mineralogist, mostly under water. 

To go to the first lake, take a shaded path north of the Derby 
road, east of the stream; it passes near a large vein of quartz, and 
then rises to the lake border. The center of the lake once had 
its fountain. Take now the path by the east side of this lake 
and soon the northern lake will be in sight. Pass over the cause- 
way by the south side of this northern lake and continue west- 
ward by a broken or partly obliterated path, and in a few minutes 
a north-and-south path will be reached ; and going south along 
it, the western lake will be soon in sight. The path leads along 
the west side of this lake to Derby Avenue. Near the west angle 
of the Park on the north side of the Derby road, a path com- 
mences which ascends through the woods obliquely to an upper 
road ; and just north of the point where it is reached, in an open 
field, the nearly vertical and westward dip of the chloritic schist 
may be examined and a fine prospect eastward enjoyed. The 



Walks and Drives about New Haven. 79 

landscape is to a great extent made up of the wooded slopes of 
the Edgewood line of hills : but, in the direction of the intersect- 
ing Derby turnpike, there is a deep downward bend in the pro- 
file, affording a distant prospect of nearly the whole city, the 
effect of which is exceedingly pleasing. One of the lakes of the 
Park forms part of the foreground. 

Now for the rocks. 

In the Edgewood Ridge, just west of Forest Street, and also 
over the Park, the chloritic hydromica schist is the rock. It is 
of interest first to ascertain from the Edgewood Ridge, the 
eastern margin of the Park, whether the dip corresponds to that 
of an anticline or arch across the Park area, or to a syncline. It 
will be found to be about 40° or 50° to the eastward ; indicating 
a rise westward and therefore an upward bend or anticline. Now 
the dip was westward on the Woodbridge Heights to the west of 
Westville, in general 10° to 80° W. : and it is the same west of 
Maltby Park. Putting the two together, they make an inward 
bend, pitching 40° to 50° eastward on the east side and 70° to 
80° westward on the west side. This is part of the evidence 
that the region of the Maltby Park valley through its whole 
course to Savin Rock is that of an anticline. Over the interior 
of the Park there is much variation in the position of the beds, 
and it is probable that the anticline is a compound one. 

On Derby Avenue, before reaching the ice-houses, outcrops of 
rock are numerous along the northern road side. Besides the 
slate, there is a blackish massive rock looking much like trap, 
and also for a short distance a dark gray limestone hardly crys- 
talline. The limestone is arched up into a low anticline and this 
fact favors the conclusion just expressed. 

The massive rock is one not often seen. It is a kind of dioryte 
— so called because it consists (as microscopically ascertained) of 
hornblende and a feldspar ; and it is named labradorite-dioryte, 
or labradioryte, because the feldspar is the species labradorite. 
Part of it is spotted with whitish crystals (or altered crystals) of 
labradorite, and is therefore a porphyritic variety of the rock. 
The crystals usually have lost their luster and cleavage and have 
probably the composition of the mineral saussurite. 

Along the path by the east side of the first lake, about two- 
thirds of the way to the northern lake, a triangular ledge, about 



80 Walks and Drives about New Haven. 

12 feet high, of dark-colored partly greenish rock will be passed 
on the right which has been much hammered on account of the 
serpentine and serpentine marble which it contains ; it is some- 
times called "Serpentine Crag." Some asbestus (fibrous serpen- 
tine or chrysotile) may be found in it in thin seams. The rock 
was once quarried on its left or north side. About 125 yards 
beyond is the north lake. By going along the eastern side 
of this lake to its northwestern, a bluff will be found facing the 
lake, which, early in the century, was extensively quarried for 
serpentine marble, or verd-antique (a mixture of limestone and 
serpentine, when pure). Large slabs were obtained and polished, 
specimens of which may be seen in the Yale College Cabinet. 
The color is yellowish-green, clouded and banded with other 
shades of green, and further variegated with yellowish-white and 
black, the last from the presence of magnetite. But the rock 
proved to be so irregular in structure, and in many parts so im- 
pure, that good blocks were difficult to obtain, hard to saw, and 
troublesome to polish ; and the quarry, not paying, was conse- 
quently abandoned. Some asbestus (chrysotile) may perhaps be 
found in the loose masses of rock along the north side of the 
lake, when the water is low ; and on the west side of the bluff, 
where there is a small brook, some pyroxene. 

A quarry of similar verd-antique marble occurs 2 miles east of 
Milford, near the turnpike. But it presented the same difficulties 
in polishing, though to a less degree and has not been worked for 
many years. The marble is very beautiful when polished, and 
differs from that of New Haven in its bluish instead of yellowish 
shade of green. This Milford quarry was the one first made 
known, it having been discovered in 1811 by Solomon Baldwin, 
then a student in the senior class at Yale, while out on a miner- 
alogical excursion with Professor Silliman. 

Much of the slate or schist of the Park will be found to be in- 
terlaminated with quartz ; and at some places there are quartz 
veins. The veins and the interlaminations have essentially the 
same origin. 

Passing the causeway south of the northern lake a place may 
be seen north of the path, shortly before reaching the north-and- 
south path above mentioned, where a quartz-vein was mined for 
copper ore. The expectant miner — it was soon after the Calif or- 



Walks and Drives about New Haven. 81 

nia fever broke out — got nothing except some nattering specks of 
ore. A few rods north on the north-and-south path, a branch 
path goes eastward up to one of Mr. Maltby's lookouts. On the 
north side of the path near the top, there is another old mine in 
a quartz vein, and here two shafts were sunk 10 or 12 feet and 
much quartz thrown out, and, it is reported, that one piece of ore 
as large as the hand was obtained. The ore is the yellow chalco- 
pyrite — of a gold-yellow color. Small pieces are now often found 
in the broken quartz, especially in the rusted pieces ; and besides 
the chalcopyrite, traces of malachite and azurite are met with and 
some pyrite. Pure chlorite is found in cavities in the quartz, as 
in other quartz veins of the park. 

On the south shore of the western lake, between it and the 
Derby road there is another spot which was once worked for cop- 
per. In the many fragments of quartz about the spot, traces of 
copper ore, and also of the common lead ore, galena, are occasion- 
ally found. 

The schist of the Park and its quartz veins and interlaminations 
are closely like those of a California gold region ; for gold, when 
in place, is usually found in quartz veins and often in a region of 
chloritic schists. But there is one important difference ; the gold 
is left out. A. C. Dill, of the class of 1840, carried 40 pounds of 
the quartz from the last-mentioned locality on his shoulder to the 
city for an examination of it for gold at the Sheffield laboratory — 
the occurrence of lead ore as well as copper ore and pyrite seem- 
ing to be favorable indications of its being true auriferous quartz. 
The trial was a complete success in proving that the gold was 
left out ! 

Returning by Derby Avenue, glacier scratches may be seen on 
the south side of the road before reaching the house at the for- 
mer turnpike gate, and farther on also on the south side of the 
road. (See the following map.) 



22. To Round Hill — A Walk or Drive. 

Round Hill is another of the prominent points on the west, 
overlooking the city. Its position, and that of Maltby Park, 
Cove River and other places in the vicinity, are shown on the 



82 



Walks and Drives about New Haven. 



accompanying map. Its height is about 304 feet. To reach it 
take either Congress or Davenport Avenue and continue west to 




Map of Bound Hill and vicinity, showing also the position of Maltby Park and 
its lakes; of Derby Avenue on the south side of the Park; Milford turnpike 
(Milford T.) south of Round Hill; the Derby railroad and its cut through Edge- 
wood Ridge, east of Cove River; the New York and New Haven railroad, and 
its cut through a low part of the same ridge ; the courses of glacier scratches in- 
dicated by arrows ; and giving also heights above mean tide. 



Allingtown on the Milford turnpike. Round Tlill is the site of 
the residence of Mr. R. M. Burwell, and a good road leads to the 



Walks and Drives about New Haven. 83 

summit from a point just north of Congress Avenue. The hill, 
unlike the bordering region, over which rocky ledges of chloritic 
schist stand out too numerously, is without a ledge through the 
whole of the upper 120 feet. Mr. Burwell sunk a well into the 
gravel of the summit, but had to go down 107 feet to get water. 
It was all the way through hard-packed bowlder-clay or till. 
Bound Hill is hence, not a hill of schist, but a high isolated pile 
made by the glacier. Another remarkable feature of the hill is 
the existence, 160 to 180 feet below the top, of a deep trench half 
way encircling it. This pile of till may have been made by de- 
position of earth and gravel from waters descending a crevasse in 
the glacier, and the trench by the denuding action of these waters. 

The summit on the Milford turnpike above Allingtown also 
has its fine view. Moreover, along the sides of the road for half 
a mile west there are glacier scratches, as indicated by arrows on 
the map. There is also a large trap-bowlder on the north side. 
Near " 140" on the turnpike (see map above) a path leads from 
the road to a spot north of it where another shaft was sunk years 
since for copper ore. Leaving this pit on the left, the strange 
trench referred to above, 50 or 60 feet deep, comes into view. 
Crossing the trench, Round Hill may be climbed. 

At the summit above Allingtown, a hundred yards north of the 
turnpike, there is a monument to Adjutant Campbell of the 
British Army, who died at the attack on New Haven of July 5th, 
1779. The British landed on West Haven point and in some 
skirmishing on Milford Hill, Campbell was shot. The only stone 
until recently was a fragment of trap, rough and unhewn, bear- 
ing the inscription, "Campbell 1779." It was put up by Mr. 
John W. Barber of this city in October, 1831, he doing the cut- 
ting on the spot. A new monument has just now been erected 
(1891). 



23. To Savin Rock — A Walk or Drive. 

The best route to Savin Rock for a drive or walk is from 
Congress Avenue out Washington Street and its continuation, 
Spring Street, to the north-and-south road at the foot of the hills 
called Campbell Avenue ; thence southward, by Savin Avenue, 



84 Walks and Drives about New Haven. 

to Savin Rock. The drive may be continued westward across 
Cove River valley just west of Savin Rock, and thence another 
mile and a half along the coast to Woodmont; thence northward 
and eastward by the Milford turnpike to the city ; or the return 
may be made by Savin Rock. 

On reaching Campbell Avenue on the way out, the extensive 
(and expensive) Derby Railroad cut may be visited. The pre- 
vailing rock is the greenish chloritic hydromica schist or slate 
already mentioned ; but at several points it graduates into the 
massive labradioryte. The latter rock, in hand specimens, looks 
like an igneous rock ; but its relation to the slate shows that the 
two had the same kind of origin. Since it consists largely of the 
fo'me-feldspar, labradorite, it was probably formed from those 
portions of the mud of an ancient West Connecticut sea that 
contained much lime (from the presence of fossils ?). It will be 
observed that the dip of the slate is small (about 25°) nearly 
northward. 

On Campbell Avenue, at the house of J. Foote, situated high 
above the avenue, a finely glaciated knoll of rock will be found 
by the north side of the house ; the rocky knoll is a beautiful 
example of what Agassiz named " Roches moutonnes " (Sheep- 
backs). Along the track of the N. Y. & N. H. Railroad, the 
same facts with regard to the rocks may be seen as in the Derby 
cut, though less perfectly displayed. At the railroad cut take 
the path going west and continue for 300 yards neai'ly to a 
north-and-south road ; thence over the field south, where there 
has long been an exposure of rock finely glacier-marked, and 
another of the "roches moutonnes" larger than that in Mr. 
Foote's yard, now, unfortunately, half buried under rubbish. 
The glacier, abrading by means of the stones in its bottom, 
wore down the schist easily, and left these scratched and polished 
knolls where the rock was harder than elsewhere. Many of the 
"sheep-backs" consist chiefly of the tough and hard labradioryte. 

The interesting points to be observed at Savin Rock are the 
fine display of ripple-marks on the sand-flats off the shores when 
the tide is out ; the abundance of blackish sand along the upper 
part of the beach, containing magnetic iron in grains and easily 
gathered by means of a magnet ; the small, nearly northward 
dip of the slates ; the many seams of quartz in the slates, in 



Walks and Drives about New Haven. 85 

some places interleaving it, as in Maltby Park ; the regular sys- 
tem of joints or nearly vertical divisional planes in the rocks ; 
the wearing away of the rocks by the action of the heavy seas ; 
a bowlder of gneiss on the western part of the main point, and 
a large bowlder of trap farther to the southwest. The sand- 
flats should be looked at as illustrations of the most common 
method of making sandstones, with or without ripple-marks, 
through all geological time. 

A study of the position of the slate, that is, its dip and 
strike, at Savin Rock, in the two railroad cuts and at Maltby 
Park, sustains the conclusion that the whole region from Savin 
Rock northward is the course of an anticline ; and the small 
northward dip — about 25° — along the center of the region is 
further evidence that the axis or ridge-line of the anticline has a 
pitch northward of about 25°. 



24. To Beacon Hill, and the East Haven Trap-dikes and 
Bowlder — A Walk or Drive. 

For the walk, the best and shortest way is by Tomlinson's 
Bridge and Forbes Avenue to Townsend Avenue a mile from the 
bridge. But carriages usually avoid the tangle of railroad tracks 
about Bridge street by continuing on Chapel Street to Ferry 
Street in Fair Haven, and then crossing the bridge southward to 
Meadow Street, where East Ferry Street (or the first road east- 
ward) may be taken to Forbes Avenue. 

Over half a mile from Tomlinson's Bridge, the road has a 
bluff of sandstone 120 yards long on its north side, and in it 8 or 
9 small trap-dikes may be counted. They vary from 4 inches in 
width to 8 feet or more, and have various directions and shapes. 
Five are 6 to 8 feet wide. One is 3 feet wide near the bottom, 
but rapidly narrows, and tapers out in a thread bent eastward 
between the layers. The sandstone beneath the road if uncov- 
ered would present an interesting display of this knot of dikes. 
In the short outcrop on the south side of the avenue only one of 
the dikes is to be found. The sandstone is for the most part 
grayish white from a discharge of the red color by the heat of 
the melted rock. A few layers of coarse conglomerate occur 



86 Walks and Drives about New Haven. 

in the sandstone, and some of the rounded stones are 10 inches 
or so across. 

On the first road going south beyond the sandstone, named 
Woodward Avenue, in the yard connected with the first house 
that stands far hack from the road, there is one of the most 
interesting bowlders of trap in the New Haven region. It is a 
rare ornament for a door yard. It is 11 feet long and 6 high, and 
weighs over -W tons. It rests with its smaller side downward on 
a projecting ledge of coarse sandstone ; and it is quite prominent 
above the surface around because the rock directly beneath it 
was thereby protected from the sun and rains. A score of years 
since, the sandstone under it had groovings that were made by 
the mass before it came to complete rest ; and their direction 
was 8. 5° W. Where it got aboard the glacier it is not easy to 
decide. The trap is precisely like that of the Judge's Cave. Mr. 
Dodd, in his history of East Haven, mentions this mass and the 
markings beneath it, and asks whether it is not of Celtic origin. 
The monument with the inscription dates far back of any 
American Celts. 

Beacon Hill is the high rounded elevation on the east side 
of Townsend Avenue. After going a fourth of a mile on this 
avenue, a road over the north flank of the hill may be taken, and 
from its highest part, the ascent may be made ; but at present 
only on foot — the layout of Beacon Hill Park being unaccom- 
plished. The view from the summit differs from most of those 
of the New Haven region in the extent of its range along the 
Sound, and also in its wide East Haven landscape. The long 
ridge on the easl extending far north under dark foliage, is 
Saltonstall ridge, on the west side of Lake Saltonstall. For the 
best landscape westward the time should be that of high tide. 
But that at low tide is interesting since it exhibits, as in a bird's 
eve view, the anatomy of the bay, — a narrow crooked channel 
between great mud flats, with a long curving sand-point project- 
ing inward from the West Haven cape. The channel is that of 
the united Quinnipiac and Mill Rivers. 

The summit affords so fine a prospect that it has been used as 
a place of lookout as well as defense fttom the earliest historical 
times: hence the name of Prospect Hill. According to tradition, 
the Indians had here a fort prior to the coming of the English, 



Walks and Drives about New Haven. 87 

and in view of this it was early named "Fort Hill." It was 
sometimes called also " Grave Hill," from the Indian burying- 
ground upon its slope. In 1775, at the beginning of the Revo- 
lutionary war, the town of New Haven (as appears by a public 
notice of that date), erected a beacon at this point, and arranged 
for giving the signal of alarm in case there should be danger of 
an enemy's attack, and thus the name " Beacon Hill " was intro- 
duced. Such an attack did come a few years later, when the 
British forces under Gen. Tryon landed simultaneously near 
South End on the east side of the harbor and near Savin Rock on 
the west. This was in July, 1779. A small fort then stood on 
the shore near the site of the present Fort Hale, and was called 
"Rock Fort" or "Black Rock Fort." It had but three guns 
and could not successfully resist the British approach. The night 
after the attack, Gen. Tryon held a position on Beacon Hill, 
" the heights above Rock Fort." On this same summit, during 
the war of 1812, earth works were thrown up for the defense of 
the harbor against the British, whose bombardment of Stoning- 
ton and threatening approach to New Haven had justly alarmed 
the inhabitants. President Day, Professor Silliman and Mr. 
James A. Hillhouse were among those who took part in the con- 
struction. The fortification was known as Fort Wooster after 
Gen. David Wooster, an officer in the Revolution, whose home 
had been New Haven. 

Beacon Hill consists mainly of sandstone, but a large trap-dike 
is the foundation upon which the old fort at the summit was 
built. The hills to the south are also of sandstone and trap. 



25. To Morris Cove — A Drive or Walk. 

Morris Cove, on the east side of the harbor, has its fine beach, 
and the way to it is along one of the best roads of the region, 
Townsend Avenue, with the Bay in sight through all its length. 
The Cove is about 2\ miles from Tomlin son's Bridge, and the 
same nearly from the Fair Haven bridge. Along the higher part 
of the road the view north is the best land prospect on the route. 
A line of heights sweeps around from West Rock by Pine Rock 



88 Walks and Drives about New Haven. 

and Mill Rock to East Rock ; and Mount Carmel lies low on the 
horizon still farther cast. 

Less than half a mile from the Cove a road goes down to Fort 
Hale on the shore, connected with the proposed Fort Hale Park, 
which is continued southward to a long bluff of trap — the " pali- 
sades," and then returns to the avenue. 

Fort Hale is a place of some historic interest. It was built in 
1809 near the site of the older Rock Fort, and was named after 
Nathan Hale, a graduate of Yale College in 1773 — a small 
round brick structure of no value in modern warfare. During 
the civil war, in view of danger from Confederate privateers, it 
was made a substantial fortification. The bold bluff of trap, 
south of the fort, makes the northern limit of the Cove. The 
rock is a less durable kind than that of East Rock, and conse- 
quently it is brown from decomposition at surface. But it is 
interesting to observe that the trap shows scarcely any sign of 
the decomposition below the level of high tide. The decay, 
which is due to the oxidation of the iron in the rock, requires 
the presence of air as well as moisture, and the tide hence fixes 
its limit. 

Along Morris Cove, not far from the water, there is a terrace, 
made of stratified sand and gravel, having a height of about 
twenty feet above sea-level. Houses of the Cove range along it. 
A similar terrace exists on the opposite side of the harbor in 
West Haven, on the line of First Street. The two terraces thus 
confronting one another, were evidently made by water passing 
through the harbor into the Sound. The terrace is believed 
to indicate a former submergence of the coast region to a depth 
of 25 feet. The time is referred to the glacial flood, or that of 
the melting glacier. . At this time the St. Lawrence valley near 
Montreal had the sea over the land up to a level of 500 feet, as 
proved by beds of sea-shells ; and lake Champlain up to 300 to 
400 feet, the lake having then been frequented by whales and 
seals; and part of the coast of Maine of over 200 feet; but 
New Haven, according to the above-mentioned record, only 25 
feet. 



Walks and Drives about New Haven. 89 



26. To Light House Point and South End — A Walk or 

Drive. 

The Old Light House is three-fourths of a mile southwest of 
the southern extremity of Morris Cove beach, and South End 
nearly a mile south of the same point. They are reached by 
different roads, and no sea-border road connects them for want 
of a bridge across a creek. 

Leaving the south angle of Morris Cove, the road to the Light 
House passes over outcrops of a whitish granite or granite-like 
gneiss ; and this is the rock of the coast region. It is usually 
rusted, and hence it is almost impossible to obtain an unaltered 
specimen. The reason why may be ascertained by examining a 
fragment ; for it will be found that the scales of black mica are 
the center from which most of the rust proceeds. The mica con- 
tains iron, and hence the rusting. It is a destructive process to 
the rock, for it ultimately takes out the mica, so that the other 
grains, those of feldspar and quartz, fall apart. Or if the change 
goes on along fractures or rifts, it divides the rocks into blocks, 
which become, by the continuance of the change, rounded stones 
or bowlders. Thus granite and gneiss — often thought of as the 
most enduring of rocks — may go to easy decay if so porous that 
it absorbs much water. 

The coast by the Light House and beyond is interesting to 
many for the sea-relics thrown up by the waves, and for the sea- 
weed views along the shores at low tide. 

The rocks to a height near high-tide level are almost every- 
where covered with a layer of barnacles, in which myriads are 
crowded together ; and wherever the water bathes them each at 
top is throwing out-and-in a cluster of slender jointed legs that 
serve as a net for gathering any food that comes within reach. 
Barnacles, as their jointed legs show, are crustaceans, and not 
mollusks. Along with the seaweeds and barnacles are also large 
clusters of mussels, brownish-black, oblong shells, two inches or 
so in length, attached to the rocks by long threads called the 
byssus; one species is smooth exteriorly (Mytilus edidis) : the 
other, radiately furrowed (31odiola plieatidd). Some of these 
mussels have a coating of barnacles. 



90 Walks and Drives about Neio Haven. 

On taking from the water a tuft of the more delicate seaweed, 
or from the tide-washed rocks, a group of mussels or barnacles, 
and putting it into a glass of sea-water, small animals of different 
kinds that were there sheltered, will he found swimming at large 
— including several crustaceans, of different genera, one or two 
species of mollusks, and perhaps some minute sea-worms or anne- 
lids. By drawing a small cambric net through the water among 
the seaweeds, then turning it inside out and rinsing the lower 
corner in a glass of sea-water, many other species will he added 
to the collection before made. The seaweed thrown up on the 
beach conceals multitudes of small crustaceans, which, if it be 
turned over, will hop away for concealment again. These sand- 
fleas, as they are called, — but undeservedly so — belong to the 
genus Orchestia, one of the genera of 14-footed or "Tetredeca- 
pod " crustaceans. They may often be seen hopping over the 
beach far away from any seaweed. After a storm, large semi- 
transparent, jelly-like masses are frequently found on the beach, 
which, if restored to the water, will show, by their radiate char- 
acter, that they are jelly flshes, or JSledusw (Acalephs), and ex- 
hibit, if uninjured, much beauty of form and delicacy of struc- 
ture. Occasionally also Actinia} or sea-anemones are thrown 
ashore, of kinds living below low water mark ; and besides these, 
mollusks and fragments of coral that at other times are rare. In 
the marsh, along the borders of the stream that enters the Sound 
just to the east of the point, there are numerous holes that are 
the lurking places of the soldier-crab or fiddler ( Gelasimus pal- 
ustris), a species broader than long, of which the males go about 
with one large-handed arm held directly in front, and looking as 
if, bully-like, always ready tor a tight. They are often outside 
in large numbers, but at an approaching tread, at once run to 
their holes. 

Most of those who visit the shore pick up its shells or gather 
its seaweeds, and many have a wider interest in the products of 
the sea. We there fort' mention the names of the more common 
kinds that may be gathered here, and at other points on the 
coast, and give such descriptions as will enable even the unscien- 
tific to identity them. 

Ai.g^e or Sea-wkki>s. — These plants grow on rocks, or the 
sands, from high-water mark down to a great depth, and some- 



Walks and Drives about New Haven. 91 

times float in the water. There are three grand divisions, based 
on their colors ; the green, the red, and the olive- colored or black 
Alga3. A few of the species commonest on this coast are : 

Fucus vesiculosus and F. nodosus, or Mock Weeds. — Very 
abundant on rocks between tide-mark, forming great bunches of 
dark olive or blackish-green flattened branches, which commonly 
bear many oval or roundish air-bladders. F. nodosus has longer 
and smoother branches than the other species. 

Laminaria saccharina, the Oar-weed or DeviVs-apron. — An 
olive-colored ribbon, 4 to 10 feet long and as many inches wide, 
having a leathery consistence, tapering at the lower end into a 
cord-like stem several inches long. Occurs on rocks below low- 
water mark, and is often cast up on the shore by storms. 

Ulva latissima or Sea-Lettuce. — Found floating, or growing 
from stones, and looks like torn pieces of pea-green and grass- 
green silk. This is the sea-weed most useful in marine aquaria. 
It is sometimes called also Sea- Cabbage. A sea-weed of like 
structure, and color, but growing in very narrow ribbons, on 
stones, is of the genus Enteromorpha. It is also useful in 
aquaria. 

The commonest red Algae are : 

Chondrus crispus. — This is the true Carrageen or Irish Moss. 
It is plentiful near low- water mark on rocks, forming dense tufts 
of flattened branches only ^ to ^ of an inch wide, which, forking 
repeatedly, become very numerous and crowded ; color dull red 
or greenish-red, and when bleached nearly white. In collecting 
it to make jelly for the sick, it must be washed many times in 
fresh water to clear it of small crustaceans, and then dried in the 
sun. 

Dasya elegans. — More delicate than any feather, with countless 
branches, the whole of the richest crimson. It is often found 
after a storm, floating near the shore. There are also other red 
species of the genera Grinnellia, Callithamnion, Ceramium, etc. 
On account of their graceful forms and red color, they are often 
mounted on cards or heavy paper, and admired under the name 
of " sea-mosses " or " flowers of the sea." 

Dr. Harvey's work, published by the Smithsonian Institution, 
gives a full account of North American Sea-weeds, while those 
"of New England and the adjacent coast are fully described in 



92 Wall's and Drives about New Haven. 

Professor Farlow's work published by the U. S. Fish Commission 
in 1881. Moreover, we have among us an excellent source of 
information on the subject in Professor Eaton. ' 

Among the animal life : 

I. Sponges. — A bright scarlet sponge {Microciona prolifera), 
an inch or two high, sparingly branched, is rather common in the 
pools ; and as it is the only scarlet species in the waters, it strikes 
the eye at once. Another large massive kind has a yellow color, 
and is the Cliona sulp/iurea. 

II. Actiniae and Corals. — Two species of Actinia, or Sea- 
anemone, may be often found attached to the under surface of 
loose stones lying on the coast near low tide level. When taken 
up, it will contract and look like a mere rounded lump of fleshy 
matter ; but if the stone with the Actinia attached is put into a 
vessel of water and left quiet, it will expand and show its flower- 
like form, presenting a circle of slender arms or tentacles, with a 
mouth at the center. The common brown one is Metridium 
marginatum ; the more slender, delicate flesh-colored one, hav- 
ing long white tentacles, is Sagartia leucolina. 

Astrangia Dance. — A coral, occasionally found in pieces an 
inch or tw T o across, on the rocks or beach, where it has been 
thrown up by the sea. It is white, and has shallow radiated cir- 
cular cells over its surface, a fifth to a sixth of an inch in diame- 
ter. It is sometimes dredged up alive off the coast, and is then a 
beautiful object when its polyps are expanded. It has all the 
characters of the ordinary coral of coral reef seas.* 

III. Mollusks. 1. Bkyozoans. — The leathery sea-weeds and 
the shells are sometimes covered here and there with very thin 
whitish crusts, which, under a lens, may be seen to consist of 
minute cabin-like cells. In a tumbler of salt water, the surface 
will soon produce a crop of delicate flowers, a circle of slender 
arms having expanded from each cell. The mouth of the animal 
is in the center of the flower. These Bryozoans are the smallest 
and lowest of Mollusks. They look externally like polyps, but 

* For a figure of the animal see " Sea-side Studies," by Mrs. Agassiz and 
Alexander Agassiz; also, Dana's "Corals and Coral Islands," page 68. Another 
very convenient sea-shore companion, containing figures of all the common shells, 
crustaceans and other species of the coasts, is "Life on the Sea-shore," by J. H. 
Emerton. 



Walks and Drives about New Haven. 93 

internally are not radiate. Besides the species forming crusts, 
there are others that are delicately branched, the branches con- 
sisting of one or more series of cells. Some of the branched 
species containing cells are Sertidarians of the division of 
Hydroid Medusa?, instead of Bryozoans. In the Bryozoans the 
cells are independent cavities while in the Sertularians they all 
connect with a tube which runs along the axis of the branch or 
stem. 

2. Lamellibranchs (so-called from the lamellar form of the 
gills, also Bivalves). Anomia glabra. — These concave, semi- 
transparent shells, of yellow, orange, and sometimes salmon 
colors, an inch or more across — are the most common kind on the 
beach, and are often called jingle-shells. Within some of them 
a thin flat shell may be found, which is the under valve of this 
bivalve. The Anomia, when living, is always attached to stones. 
or to other shells, and especially to the oyster, and the attach- 
ment is made by means of a muscle which passes through a large 
hole in the under valve. Anomias, Crepidulas, sponges and 
bryozoans may often be found alive on the fresh oysters in an 
oyster shop, covering the outside of the shell ; and it is only 
necessary to put the oyster into a bowl of pure sea-water (such as 
may be obtained off the end of Long Wharf) to make them show 
out their characteristics. 

Mytilus edxdis and Modiola plicatula, or Mussels. — These are 
mentioned above. 

Ostrea Virginiana. — The common oyster. 

Pecten irradians. — The common Scallop of the coast. A nearly 
circular, shallow shell, 1 to 2 inches in diameter, with one side, 
that of the hinge, nearly straight, and the exterior surface 
radiately furrowed from a point near the center of the hinge-line. 
The shells are common on the beach. It occurs living over some 
of the outer flats and in shallow water. 

Mercenaria (formerly Venus) violacea. — The common round 
clam. While the oyster is always a stationary animal, being 
fixed in the mud or to the rocks, the clam has locomotion, and in 
this and other ways shows its superiority in rank. 

Argina (formerly Area) pexata. — A shell, one to two inches 
across, shaped much like the common clam, but longer in propor- 



94 Walks and Drives about New Haven. 

tion, and having the outer surface radiately ribbed, covered when 
fresh with a black scaly coating, and the hinge surface furnished 
with a multitude of small teeth. 

Scapharca (formerly Ami) transversa. — Like the preceding in 
its numerous small teeth along the hinge-surface, but more oblong, 
flatter, and having an abrupt angle between the side of the shell 
and the upper part behind the beak ; this angle extends from the 
beak obliquely downward and backward. 

JZemimactra (formerly Mactra) solidissima. — Resembles the 
round clam, but is a little more oblong, and has a triangular 
spoon-shaped cavity at the center of the hinge-surface. The 
larger shells are often four inches long, but great numbers on the 
beach are less than an inch ; the latter are young shells. 

Mult nia (formerly Mactra) lateralis. — This is a small shell, 
usually about half an inch long, which closely resembles the 
young of the preceding. It is more swollen, and each valve has 
a sharp ridge passing from the hinge to the outer edge near one 
end. It lives on the mud flats, just below low-water mark, in 
great abundance. 

Mya arenaria. — The common long clam. The shell is nearly 
twice as long as broad, and when the valves are closed it gapes at 
either end. Those along the beach vary from half an inch to two 
and a half inches and more. It lives in sand-flats near low-tide 
level. The vertical holes often occurring in such flats, half an 
inch or less in diameter, usually lead down to a long clam ; the 
tread of a person over the flat often occasions a spurt of Avater 
out of the hole, arising from the clam suddenly closing its shell 
and throwing out the sea-water from the cavity about the body, 
in which the tiills or branchiae are contained. 

Ensitella (formerly Solen) Americana. — A long narrow curving 
shell, called from its shape Razor Shell. It is often five or six 
inches long. The length is about five times the breadth (or more 
properly height). The shell has a delicate shining epidermis ; 
and when closed it gapes at either extremity like that of the 
Mya. 

3. Gasteropods (Univalves). Crepidula j'ornicata. — A con- 
cave shell, somewhat boat-shaped, having a shelf in the smaller 
end, or like a boat with a seat behind. It is one of the most com- 
mon shells of the beach. When living it is commonly attached 



Walks and Drives about New Haven. 95 

to the shell of the oyster, but occurs also on other shells, and even 
on stones. There are also two other less common species of 
Crepidula. One, the C. ungitiformis, is distinguished by its 
white color ; it lives inside of the old shells of the Fulgur and 
Sycotypus. [See below.] 

Neverita (formerly Natica) duplicata. — A spiral shell, with 
the spire only very slightly prominent, and no beak at the other 
extremity ; the form is nearly round, though not so high as 
broad. Adjoining the inner margin of the aperture the shell is 
abruptly thickened. Often over two inches in diameter. 

Littorina palliata. — A small rather thin shell, light yellow to 
dark brown in color, with a short spire, nearly round aperture 
and no beak. It is an eighth to a third of an inch across. It is 
pretty sure to be caught in a cambric net. Another species, L. 
littorea, the European periwinkle, has recently become naturalized 
along our shore and is everywhere very abundant. It is similar 
in form but much larger, thicker and darker in color. 

Fulgur (formerly Pyrula) carica. — A large spiral shell with a 
long beak and prominent spire, sometimes four inches across and 
six or more long, having a row of tubercles on the body of 
the shell and the whorls of the spire. Fragments of this shell 
and of the following are common on the beach, and after a storm 
living specimens may sometimes be obtained. 

Sycotypus (formerly Pyrula) canaliculus. — Like the preced- 
ing in size and general aspect, but the spire has a deep angular 
channel along the line of the ordinary suture between the whorls. 
There is often found on the shore a long membranous cord, bear- 
ing a series of membranous cells, about f inch across, attached 
crowdedly to one side of it, but somewhat spirally. It is the 
spawn of this or the preceding species ; each of the cells contains 
a large number of eggs or young shells. 

Urosalpinx (formerly Fusus) cinerea. — A whitish or yellow- 
ish-white shell, an inch or so long, with a prominent spire and 
beak. The whorls as well as the body of the shell are crossed 
vertically by prominent ridges and also spirally with fine ridges. 
Common in the pools and shallow waters. It is popularly called 
the drill or borer, as it is the shell which bores holes into oysters 
to suck out the juices ; it has for this purpose a mouth, armed 
well with minute teeth, which may be elongated into a kind of 
proboscis. 



96 Walks and Drives about New Haven. 

llyanassa obsoleta. — The small black shell that may be seen 
everywhere over the flats when the tide is out. It lias a rather 
prominent spire, quite a short beak, and the aperture within is 
shining black. The outer surface is marked spirally with very 
faint ridges, which become rows of points on the spire. Length, 
two-thirds of an inch. The flats after they have been bare for an 
hour are usually crossed in all directions by their tracks. 

Tritia (formerly Nassa) trivittata. — Resembles the preceding, 
but is a more slender shell, is nearly white, and has the surface 
finely chequered owing to the crossing of delicate vertical and 
concentric spiral lines or ridges. Occurs along the beaches. 

III. Articulates. — The water Articulates are mostly either 
crustaceans or worms. 

Crustaceans. Libinia canaliculata. — A large crab, triangu- 
lar or obtusely pointed in front, with rather long legs. Common 
along the rocky shores at the Light House, and alluded to above. 
Some specimens have the bod}' 4 or 5 inches long, and the spread 
of the legs 15 inches. 

Cancer irroratus. — Much broader than long, Avith the front 
semicircular, and nine slightly prominent, broad teeth on either 
margin outside of the tooth that adjoins the eye. Breadth 2 to 4 
inches. The back shell, or carapax, is often found on the 
beaches. 

Platyonychus ocellatus. — About as large as the last, but nearly 
as long as broad, with a semicircular front, and five very promi- 
nent and somewhat distinct sharp teeth on the margin outside of 
the eyes, and three between the eyes. A beautiful species, spotted 
with email rings of purple. It is often called lady-crab. The 
carapax is not unfrequent among the shells of the beach. Lives 
in shallow water among the eel-grass. 

Carcinus Mcenas. — Like the preceding nearly in form ; but the 
five teeth outside the eyes are less prominent and contiguous, and 
the front, which projects a little between the eyes, has no sharp 
teeth, and has at its center a slight notch instead of a tooth. 

Panopevs Sayi and P. depressus. — These two species are called 
mud crabs. They are usually about an inch across and both have 
the large claws black. The last-named has the hack most flat- 
tened. Both are very common under stones on muddy shores 
and among oysters. 



Walks and Drives about New Haven. 97 

Gelasimus palxistris. — The soldier-crab, mentioned above. 
There is also a second species, G. pugilator, found along the 
beach, just below Tomlinson's bridge. 

Eupagurus longicarpus. — The hermit-crab. A much larger 
species, E pollicaris, lives in the shells of the Fulgur and 
Sycotypus. 

The Lobster (Homarus Americanics) , and the crab of the mar- 
ket ( Callinectes (or Lupa) hastatus), are not often found on the 
Light House beach. They sometimes are caught in moderately 
deep water in the harbor, but come mostly from the coasts out- 
side. The hind legs of the crab are swimming legs, and for this 
purpose the last joint is broad, elliptical and thin. 

Squilla empusa. — A very singular, elongated crustacean, with 
remarkable comb-like claws, is occasionally thrown on the beach 
at South End. It lives in burrows, below low-tide level and 
grows to the length of six or eight inches. 

The above (with all crabs, shrimps, or the like) are ten-footed 
or " Decapod " crustaceans. To another group or order, that of 
the 14-footed or " Tetradecapod " crustaceans belongs, as has been 
stated, the Sand-flea or Orchestia of the beach. Its remarkable 
feats at leaping are accomplished by means of its tail, or rather 
the abdomen or hinder portion of the body. Among the small 
crustaceans that may be collected with a cambric net, as ex- 
plained, there are other related species, of the group of Gam- 
marids, which swim with great rapidity, either by jerks by a 
shove of the tail, or more steadily by the use of swimming legs 
projecting from the under surface of the abdomen. 

In another higher group of the 14-footed species (called from 
the nearly equal feet Isopods) the abdomen is much shorter, and 
locomotion is performed in the more legitimate way by the use of 
legs ; and specimens of these also will probably be found in the 
bottle or glass of water which contains the rinsings of the net. 
While the former are swimming species, the latter are crawling. 
The former may sometimes be found scrambling over the bottom 
of the glass, but will soon give a jerk and be off swimming. 

Entomostracans. — A tumbler of sea-water from the pools at 
low tide, especially if taken up from among the sea-weeds, is sure 
to contain some minute species of this lowest order of Crustaceans. 
Some are of the Cyclops tribe, as certain one-eyed infinitesimals 
(a line or less long,) are called (actually two-eyed, but the two 



98 Walks and Drives about New Haven. 

are on a single spot of pigment, and look like one) ; and others, 
even more minute, have bivalve shells like a clam, and are of the 
tribe called Ostracoids, from the Greek for shell, and whence 
comes also the more familiar word oyster. They often lie on the 
bottom of a tumbler as if without life. But soon, antennae are 
run out in front, and legs appear along one edge or side, and off 
they swim in lively style. 

JBamacles have been mentioned above. They are among the 
lowest of Crustaceans, being so low as to live a stationary life, 
like plants. In the young state, when half a line or so long, they 
swim at large for a while, and look like Ostracoids. But after a 
few days, they light on the rocks or sea-weeds, by means of a 
pair of arm-like antenna? proceeding from the head, and in that 
act lose their freedom. They soon grow beyond the size which 
their diminutive life-systems could wield or give locomotion to, 
secrete a box-like stony envelop around the sides of the body, and 
two moveable valves at the top to close or open it at will ; and, 
thus boxed in, they are at almost incessant work, if the w r ater 
covers them, throwing in and out a net-like group of legs to 
catch their prey. Whenever the tide recedes and leaves them 
bare on the rocks, the valves close tight, and water enough is 
thereby confined to keep them in good condition. 

Limuxoids. The Horse Shoe {Limulus occide?) talis) differs 
from Crustaceans in many respects, and is the nearest of living 
species to the ancient Trilobites. It is often met with on the 
beach in dead specimens, both young and old, and may be fished 
up alive from shallow depths. They are often 15 inches broad, 
and, the long spine-like tail included, twice this in length. The 
form of the front part of the shell beneath is a little like the hoof 
of a horse, and hence the popular name. The first or basal joints 
of the legs play the part of jaws, and they are the only jaws that 
the mouth is furnished with ; in other words, the jaws in this de- 
graded species are, through enlargement and elongation, made 
into good legs. They are well provided with the means of sight. 
The shell has above one front spine, and posterior to this a trans- 
verse row of three spines ; cither side of the front spine there is 
a single eye ; and on the outside of the corner of the three spines, 
a large convex compound eye, combining, as may lie seen under a 
lens, a large number of eyes, each of the minute spots in the 
compound eye having a separate crystalline lens. 



Walks and Drives about Neio Haven. 99 



27. To Mansfield's Grove in East Haven, and Short 
Beach and Double Beach in Branford. 

East Haven is reached by following the road eastward from 
Toralinson's bridge, or by turning into this road if the Chapel 
Street route is taken. At East Haven go southward by the east 
side of the public square. After the turn eastward pass two roads 
coming in from the south ; then take the third in order to go to 
Mansfield's Grove, a beautiful spot ; or continue eastward to the 
bridge across Farm River. The roads over this southeastern 
part of East Haven go partly through thin or half grown woods. 

Farm River, in this its lower part, is really a small fiord ; it 
has banks of granite-like gneiss, and seaweeds, barnacles and mus- 
sels are growing on the rocks, as at the old Light House. It is 
sometimes called Stony River. 

From the bridge it is hardly a fourth of a mile south to Short 
Beach, and about a mile east and then half a mile south to 
Double Beach. 



28. Around Saltonstall Lake from East Haven to Foxon 
and Fair Haven — A Drive or Long Walk. 

Saltonstall Lake, the scene of college boat races, was called in 
colonial times the Great Pond, and Furnace Pond, although one 
of Nature's smaller lakes. Its present name commemorates the 
residence on its borders for awhile after 1709, of Gurdon Salton- 
stall, governor of Connecticut from 1708 to 1724, who was instru- 
mental in procuring the removal of Yale College from Saybrook 
to New Haven. His portrait hangs in Alumni Hall, and a sketch 
of his life, by Prof. J. L. Kingsley, may be found in the New 
Englander, vol. ii, 1844. 

Saltonstall Lake is three miles long and 400 to 500 yards wide 
(Plate I) ; and although so narrow has a depth at one place (ac- 
cording to the Bache map) of 107 feet. Lying by the east foot 
of the long bow-shaped Saltonstall Ridge, it owes much of its 
beauty to this high forest-covered border. From East Haven 
village, a fine view of it may be obtained by taking the road 



100 Walks and Drives about New Haven. 

northward to a point on Saltonstall Ridge just beyond the rail- 
road — the distance half a mile. 

In the drive around the lake to Foxon the chief feature in the 
scenery is the ridge instead of the lake. Going through East 
Haven eastward the little stream is crossed b} r which the Lake 
discharges into Farm River, and in this discharge it passes over 
a low part of the trap-dike. " Iron works " were here established 
by the first generation of colonists, " bog-ore " from North Haven 
and elsewhere having been brought to supply the furnace. Hence 
came the name of " Furnace Pond." The works were discontin- 
ued in 1679-80, and a grist-mill soon after established on the site. 

Having passed the south end of the lake, take the first road 
northward. It passes near and in some places over a low inter- 
rupted dike or trap, the lake lying really between two nearly 
parallel trap-dikes. After two miles along it, a road comes in 
from the east. At this place, there is by the roadside, a ledge of 
coarse sandstone in which are a few stones of trap, proving, like 
other cases in the vicinity, that some of the sandstone of the 
region was made after the eruptions of trap had commenced. 

The road continues northward for half a mile, then goes 
eastward, and then northward again, and, soon after the last 
turn, commences an ascent to the summit of Saltonstall Ridge. 
A shallow pond to the west is overlooked before reaching the 
trap of the ridge. On commencing the descent northward, take 
the first road west and follow it in its bend northward across 
Farm River to the small village of Foxon. From Foxon the 
road is nearly straight to the north -an d-south Fair Haven road, 
about If miles distant ; and from the junction with this road it 
is nearly a mile to the Fair Haven bridge over the Quinnipiac. 

The deep trench of Saltonstall Lake, with a high trap ridge on 
the west, and another parallel line of trap near the eastern bor- 
der, looks as if it had once been the course of a river. But the 
outlet in East Haven is over rocks above tide-level ; and that of 
Farm River nearer the coast has a rocky bottom at shallow- 
depth ; and hence if the land were elevated, the water in the 
Lake would not run out, so that river action could not have made 
it. The old glacier might have ploughed out the sandstone to 
the required depth ; and this is probably the true explanation. 



Walks and Drives about New Haven. 101 



29. To Branford and some strange hills of Bowlder 
Conglomerate — A Walk or Drive. 

Through the village of Branford passes the boundary line be- 
tween the Jura-Trias Sandstone formation and the gneiss of the 
region south and east. Near the boundary on the limits of the 
village, and partly within the gneiss, occur the easternmost of 
the trap-dikes. These dikes have several points of great interest, 
briefly mentioned on page 33. About l£ miles northeast of these 
dikes there are several low hills which consist of rounded stones 
of trap, sandstone, gneiss and other rocks, some of these stones 2 
to 3 feet in diameter. The accumulation looks much like bowl- 
der deposits of the Glacial period. The dikes and the hills of 
bowlder conglomerate are described in the paper by Mr. Hovey, 
referred to on page 33 ; and in it the reader will find a full ac- 
count of them and a map showing their location. The hills of 
conglomerate are of unascertained origin ; and, since they have 
great interest, one way to reach them is here stated. In the pre- 
ceding excursion a small pond is alluded to as seen west of the 
road just before crossing Saltonstall Ridge. By taking the road 
that goes eastward a little north of this place, and continuing 
eastward for 2\ miles (passing on the way one southward road), 
and then turning southward, after going three-quarters of a mile 
the first house on the road will be reached. One of the hills will 
be found to the west, by passing through the barn-yard north of 
the house and continuing on for a dozen rods or so. The hills 
are covered with forest trees and should be ascended to the crest 
of rock at the summit. Such agglomerations of large stones of 
trap, sandstone and gneiss cannot be volcanic ejections. No 
stream of water could have transported and deposited them unless 
it were a great torrent descending a steep valley ; and the aid of 
ice also would seem to be necessary. Gneiss exists to the east- 
ward and northeastward, and so also trap and sandstone ; but 
there are no steep westward slopes there descending from icy 
heights, and no known record of any in earlier time besides the 
facts here presented. 



102 Walks and Drives about New Raven. 



30. To the East Haven Sandstone Quarries — A Walk or 

Drive. 

Out Chapel Street to the Ferry Street bridge in Fair Haven. 
From the bridge, the top of a derrick may be seen over the high 
hill to the eastward. For the walk from the bridge the course is 
directly east, across the railroad and up the hill. For the drive, 
go down Meadow Street to Center and then a short distance 
northward on Prospect street. 

But before going farther, the rocky point west of the river be- 
low the bridge deserves consideration. This spot was the " Ferry 
Point " or " Red Rock " of early colonial times. The name " Old 
Ferry Point," which is still sometimes given to " Red Rock," 
commemorates the site and the mode of crossing to East Haven 
prior to 1790, when the more northern of the two Fair Haven 
bridges was built. The first road out from New Haven followed 
the present course of State Street, crossed " Neck Bridge," (that 
of State Street over Mill River) then turned to the right 
and went diagonally across " the Neck " to the ferry ; and on 
the East Haven side, it continued toward the iron-works at the 
lower end of Lake Saltonstall or "Furnace Pond." The selec- 
tion, in 1638, of the center of the New Haven plain for the site of 
the future city tended to draw off the population from the banks 
of the Quinnipiae. But the harbor privileges of the latter place 
have always given it importance; and now, through its oyster 
trade, sandstone quarries and shipbuilding, the settlement has be- 
come the largest of the villages about the bay. Further, the red 
sandstone at this place is a good example of the ordinary charac- 
ters of the rock ; its eastward dip, and its variation in texture, 
some layers being a conglomerate, and isolated stones in it a foot 
or more in diameter. It exhibits also a case of bleaching to 
white the red color of the rock. The whitish streak seen along 
the top of a layer owes its color to the waters that soaked down 
from the soil above and flowed along the surface of the layer be- 
cause the layer was a little clayey. Such waters carry along a lit- 
tle organic matter from the soil and this has the property of tak- 
ing oxygen from the red iron oxide (Fe 2 :) ) which is the coloring 
matter, (reducing Fe 2 O a to FeO), and supplies also an organic 
acid or carbonic acid for combination with the iron (FeO); and 



Walks and Drives about New Haven. 103 

so the red oxide loses its color. Isolated spots of a similar color 
are common in the red rock, which some fragment of fossil wood 
may in a similar way have produced. 

The top of the hill on the way to the derrick affords a fine 
prospect westward and northward. It includes the wide region 
from Mt. Carmel to the Sound ; and near the middle of it stands 
East Rock like an island in the great plain. As one of its 
striking features, Sachem's Ridge is projected against Pine Rock, 
covering all but its top, and the larger mansions of the ridge look 
like palaces built about its heights. 

At the quarry, across the road, the general features of the sand- 
stone formation are well displayed, (l) The granitic origin of 
its constituents, — only mica (of the three, quartz, feldspar and 
mica) being rare ; and the reddish feldspar grains generally show- 
ing good cleavage and luster instead of being decomposed. (2) 
The eastward dip of the beds of !5° to 25°, showing, like all the 
rest of the outcrops of sandstone in the Connecticut valley, that 
the beds had been shoved up out of their original horizontal posi- 
tion. (3) The existence of nearly vertical divisional planes or 
joints, from top to bottom of the quarry — a great convenience to 
the quarryman. Further, on the west margin of the quany, there 
are large surfaces covered with glacial scratches, having the 
direction N. 15° to 18° E. For a long time after the quarry was 
first opened there was a rounded " ogee " of sandstone, 20 to 30 
feet wide, and 300 feet long, which had been shaped by the 
ploughing action of the glacier. Every new removal of the soil 
opens to view other scratched, planed or ploughed surfaces. 

Going eastward from this quarry over the hills 500 yards, 
another quarry is reached. It opens out on the road next east, 
and the place is therefore accessible to a carriage. The same 
features are here exhibited as at the first quarry, that is the same 
granitic sandstone, the same eastward dip, and extensive joints. 
The surfaces of the joints, large and small, are usually smoothed 
and grooved through mutual friction, and are good examples of 
the " slickensides " of miners. Besides this, these smoothed 
scratched surfaces have generally a white coating, which was 
derived, it is believed, from the grinding of the feldspar of the 
sandstone into a paste and its subsequent hardening. At this 
quarry the upper surfaces of the sandstone layers also are slicken- 



104 Walks and Drives about New Haven. 

sided for hundreds of square feet, showing that there was move- 
ment of layer over layer as well as slipping along multitudes of 
fractures, when the position of the sandstone was changed' from 
horizontal to a dip eastward of 15° to 25°. 

A very narrow trap-dike intersects the sandstone of the quarry, 
the rock of which is much decomposed and broken into small 
fragments. Extensive glacial scratches have also been visible at 
this quarry. The above are common features through all the 
quarries of the region. 

The return may be made by following the road northward and 
then turning eastward to Fair Haven ; or by taking the road just 
south across the railroad, and then going first east and then south 
to Forbes Avenue and Tomlinson's bridge. 



31. Sandstone Ledges and Trap-dikes along the Shore 

Line Railroad Track to Saltonstall 

Lake — A Walk. 

The part of the Shore Line railroad here in view may be 
reached by going out Chapel Street, crossing the Ferry Street 
bridge in Fair Haven, and continuing on to the crossing of 
Meadow and Center Streets. Between this point and Saltonstall 
Lake the railroad cuts through seven hills or ledges of rock, and 
it is a good opportunity for the examination of the sandstone 
and its intersecting trap-dikes. 

The first ledge consists wholly of sandstone. This sandstone, 
it will be noted, is much fractured, and all the pieces have their 
surfaces covered with scratches or slickensides, showing how gen- 
eral was the slipping of parts attending the upturning of the 
sandstone. 

The second ledge has a trap-dike 22 feet wide cutting through 
hard sandstone. In the third, a trap-dike 1 1\ feet or 18 feet wide 
occupies almost the whole of the ledge, there being but little 
sandstone at each end, and that much obscured by the baking it 
has undergone. The trap is very much cracked and decomposed. 
The fourth ledge is the largest of the series, and consists only of 
sandstone in thick layers. The fifth ledge lies wholly south of 
the road, its northern end only having been cut off. It is one of 



Walks and Drives about New Haven. 105 

the larger trap-dikes of the region. In the field on the opposite 
side cf the railroad there is another hill of trap, and farther to 
the northeast still another higher ridge. Between the latter and 
the railroad there is a low hill of brick-red sandstone. The road 
next passes over a long range of East Haven meadows little 
above sea-level. 

The sixth ledge is low and long, and consists of sandstone ; but 
in its eastern part, where the sandstone is not well exposed to 
view, there are loose blocks of trap on either side of the road. 

A short distance to the eastward, the carriage road — but not 
the railroad — cuts across the south end of a trap-ridge which ex- 
tends far north parallel to the Saltonstall Ridge ; it is separated 
from the latter only by the valley of Farm River. The section 
of the trap and sandstone along the road is the very interesting 
one represented in its eastern part by the figure, page 32, in which 
the trap rests on upturned ledges of sandstone, proving that the 
upturning had taken place before the eruption of the trap. ' In 
the western part of this cut the trap looks as if it came down to 
the level of the road ; but whether this is so from undermining, 
or whether it is the original position, it is not easy to say. 

The trap of this Farm River ridge, like that of Saltonstall 
ridge, is more or less amygdaloidal — that is, it contains small 
nodules of some white crystalline mineral distributed through 
the mass. The mineral is mainly calcite (carbonate of lime), and 
occasionally quartz. These nodules are often nearly cylindrical, 
and two or three inches long. Many of the loose, half -decom- 
posed masses of rock are full of holes arising from the removal of 
the calcite. When the trap came up in the melted state its outer 
portion became filled here and there with cavities through the 
expansion of steam or of vapor of some kind. These cavities 
subsequently became occupied with the calcite and quartz. This 
is the usual mode of origin of an amygdaloid — the name, derived 
from the Latin for almond, alluding to the almond-like form 
presented sometimes by the nodules, and having no reference to 
their mineral nature. 

The ovoidal holes were undoubtedly made by vapor of water, 
or steam, like those of cellular lava ; but the cylindrical were 
probably a result of the explosive vaporization of liquid car- 
bonic acid, as stated on page 33. The trap of the Saltonstall 
8 



106 Walks and Drives about New Haven. 

Ridge— the seventh in the series — is amygdaloidal to the east 
ward alongside of the railroad and at other |><»iuts od the borders 
of the lake. 

The trap of Farm River and Saltonstall ridges, and of nearly 
all of those of East Haven, and of many to the north, has little 
luster and decomposes easily to a yellowish brown earth, quite 
unlike that of East and West Rocks ; and it is so much broken 
up that the glacier had no chance to get a large bowlder from 
them. When examined in thin slices microscopically, instead of 
exhibiting the constituent minerals in a transparent condition, 
like the trap of West Rock, they are found to be clouded or 
opaque, and there is much green chlorite and little unchanged 
pyroxene. This alteration of the trap was produced by means of 
water or steam — for the chlorite formed is a hydrous mineral, 
and so are some of the other products. The water gained access 
to the trap of these dikes while the melted rock was on its way 
to the surface. The melted trap came up from great depths, 
through fissures intersecting first crystalline rocks, and then, 
with few exceptions, through sandstone. The " great depths " 
did not supply the moisture ; for if so, all the trap of the New 
Haven region should have been essentially alike in amount of 
water. The crystalline rocks did not give it, for the trap of the 
dikes intersecting only the crystalline rocks contains no more 
water than that of West Rock. It must therefore have been 
taken in from supplies of water at the bottom of the sandstone 
or at levels within it between its loosely packed beds. 

Besides water, the trap while on its way up received some 
carbonic acid. This it may have taken from limestone adjoining 
some part of the walls of the fissure. It also gathered in mineral 
oil or petroleum from carbonaceous shale; for inspissated bitumen 
occurs in amygdules elsewhere. The calcite making amygdules 
was made from lime afforded by the labradorite or pyroxene, con- 
Btituents of the trap; it combined with the free carbonic acid and 
so made the calcite. The quartz or agate in other amygdules 
came from the silica set free in the alterations undergone by the 
constituents of the trap ; for chlorite, the most common product, 
uses only two-thirds of the silica of pyroxene. 

Saltonstall Ridge may easily be ascended from the railroad for 
a ramble through the woods, and the enjoyment of views along 



Walks and Drives about New Haven. 107 

the lake ; but there are no columnar precipices to be visited, and, 
owing to the forests, no points for good distant prospects. The 
distance along it to Foxon is 3 miles; from Foxon to Fair Haven 
2f miles. 



32. To Rabbit or Peter's Rock — A Walk or Drive. 

The way to Rabbit Rock is by State Street, across Mill River, 
and then, after passing the railroad track, across the Quinnipiac 
and the Quinnipiac meadows. Beyond the meadows eastward 
the road makes an intersection, like a narrow letter x, with the 
East Haven road from Fair Haven. Continue on beyond this 
intersection, crossing a little brook, and soon after enter to the 
right, where a road and path lead to the summit of the Rock. 
The distance from New Haven is about 4^ miles At Rabbit 
Rock there is the most remarkable display of columns of trap 
about New Haven. The columns are three or four feet in 
diameter, and some of them are very nearly regular hexagons. 
They form a bold front to the west, and make a polygonal pave- 
ment over part of the summit. 

The Rock may be reached also from Fair Haven, from which 
it is three miles distant. 

The view from the Rock is literally panoramic, taking in the 
Avhole horizon. It includes the Sound far to the southeast, near 
Branford ; the whole range of the Quinnipiac meadows ; Mt. 
Carmel and the Hanging Hills of Meriden on the north ; the 
isolated East Rock group of heights, in the great plain ; the 
West Rock Ridge ; the Woodbridge range to the south ; with 
numerous spires, and various clusters of houses in all directions, 
besides the w r ide-spreading city of New Haven. 



33. Up the Quinnipiac to North Haven and its Brick- 
yards — A Walk or Drive. 

Crossing Whitney Lake above Whitneyville it is only a short 
walk or drive to the Quinnipiac Valley. The brickyards com- 
mence south of the railroad station of Quinnipiac, and occur at 
intervals from there to North Haven, on the east side of the 



108 Walks and Drives about New Haven. 

meadows, and also to a less extent on the west side. The 
general characteristics of the clay may be w,ell studied at the 
clay pits of Captain Crafts, at the Quinnipiac station : its thinly 
laminated structure, with each little layer one-third to half an 
inch thick, consisting of a bottom portion of tine sand and sandy 
clay, and the rest of the fatty clay. Besides clay, the deposit 
has turned out an occasional glacier-scratched bowlder, and one 
from a depth of 6 feet that is 4 feet in diameter. In addition, 
two leg bones of Reindeers have been found at Captain Craft's 
pit, which are described by Prof. Marsh as a shoulder-bone 
(humerus) and a bone of the right leg (tibia), of the true Arctic 
Reindeer {liangifer tarcoulus), not of the Canadian Caribou. 
Moreover they belonged to two different individuals. 

There are also concretions of flattened or lenticular form. 
They are often called clay-stones, but are really calcareous. 
Such concretions were probably made from land or freshwater 
shells, which in a ground-up state were deposited with the clay. 
Through the dissolving power of percolating waters, the material 
of the ground shells passed into solution, and the concreting 
action went forward. The concretions are widest horizontally, 
or in the direction of the layers of the clay, because water per- 
colates easily in this direction and with comparative difficulty 
through the layers vertically. 

The clay-pits in the vicinity of North Haven afford similar 
facts, except that no Reindeer bones have yet been reported from 
them. 

The geological history of this Quinnipiac region is interesting. 

This broad tidal region of the Quinnipiac meadows, lying now 
at sea-level up to North Haven, but deep below the sea-level in 
peal and mud, and hemmed in on the south across from Snake 
Rock to the Fair Haven hills by the sand and gravel deposits of 
the New Haven plain, excepting a narrow channel for the river, 
must have been, at the time of the deposition of the clays, a great 
bay with a shallow outlet, in which the river waters, in times of 
moderate floods, brought sediment from the region just north, 
and dropped first the sand, and then, during the lake-like quiet 
which followed, the finer clay. It need not have been a lake, 
for a basin or bay with shallow outlet would have afforded the 
required conditions. 



Walks and Drives about New Haven. 109 

But the scratched bowlders dropped from floating ice to the 
bottom, while deposition was in slow progress, show that the time 
of deposition was close on to the Glacial period ; probably soon 
after that submergence of Southern Connecticut of 25 feet, re- 
ferred to on page 88, but before the flood from the melting 
glacier began. The ice was still over the region or on its bor- 
ders, and Reindeers found an arctic climate and all else to suit 
their tastes. The New Haven plain had not been made, for the 
glacier was yet to melt and discharge its freight of sand and 
gravel. 

Moreover, the Quinnipiac was then a small stream compared 
with Mill River (p. 57), and long continued to be small and feeble. 
Mill River, in contrast, was all the time a dashing torrent, the 
slope of its bed from Mt. Carmel down 10 feet a mile. 

The glacial flood, when fairly under way, affected both streams, 
but in ways very unlike. It is a remarkable fact that the differ- 
ence in the force and work of the two streams is registered in the 
deposits of the New Haven plain south of Snake Rock ; and 20 
years since, the evidence was visible in the cut made through it 
for the New Haven & Hartford railroad ; and it would now be 
visible were it not for the slides of sand over the face of the cut. 
Up to a height of 25 feet, or the level of the submergence above 
referred to, the sands there deposited were those of the Quinni- 
piac. Mill River also worked in its own channel; each was inde- 
pendent of the other. But on reaching this level below East 
Rock, Mill River manifested its superior volume and power by the 
throw of its waters, sand and gravel across the broad Quinnipiac 
valley ; and from this time on, as the flood augmented in violence, 
it controlled all Quinnipiac deposition, until the Fair Haven part 
of the New Haven plain was finished off at its level of 40 to 45 
feet above mean tide. And at the same time it carried on its 
work over the central part of the New Haven plain to the bay.* 

The Quinnipiac River regained its superiority at the close of 
the melting. When the flood was at its height, the depositions of 
sand and gravel along the course of the great Mill River reached 

* The evidence of the facts, here stated (which is based on the stratification of 
the beds and the quality of the material), is given in the paper on the Topograph- 
ical Features of the New Haven Region, referred to in a foot-note to page 2, and 
also in the American Journal of Science for September, 1875, volume x, page 173. 



110 Walks and Drives about New Haven. 

nearly flood-level across the valley, leaving only a narrow channel 
for the stream. But as the flood declined these deposits became 

a harrier to the diminished stream ; and when the ice disappeared, 
and the Tariffville ice-dam broke away, the waters of the Farin- 
ington River turned northward to their old route; the Quinnipiac 
regained its channel ; and to Mill River was left for water sup- 
ply only the small part of the valley south of Cheshire. 

During the continuance of the Glacial flood, Mill River had a 
length of 75 miles, it commencing at a height above 2000 feet in 
the Berkshire hills, and its drainage area was 450 square miles ; 
while the Quinnipiac. had then a length of only is miles and a 
drainage area of Go square miles. After the flood, the length of 
Mill River was reduced to 15 miles and its drainage area, to 50 
miles ; while the Quinnipiac became a stream 33 miles long and 
120 square miles in drainage area.* 

The bricks of the brick yards also are instructive. It is well 
to observe the stages in the manufacture ; and to know that the 
clay becomes red in baking simply because the heat drives off the 
water combined with the iron in the clay, or, less frequently, the 
carbonic acid — thus reducing the iron to the red oxide (p. ). 
When overheated in the baking, the brick become partially 
fused, lose their red color, and sometimes run down in coarse 
stalactites. This shows that the North Haven clay contains 
something besides pure clay and quartz sand ; for these are 
infusible materials. Iron is present and this promotes fusibility. 
But the facts indicate the presence of some other ingredients. 
An analysis in L889 by Mr. O. H. Drake of the Sheffield Scientific 
School of a half-fused brick from the southern yard obtained the 
following for the composition : Silica 05 89, alumina 18 - 98, iron 
sesquioxide 2 '97, iron protoxide 132, manganese protoxide 0.22, 
lime 2-29, magnesia 2-56, potash 3-15, soda 2-96 = 100-32. The 
amount of potash in the brick corresponds to at least 20 per 
cent, of feldspar in the materials. Nothing is added to the 
clay for brick-making except about 20 per cent, of sand and 
anthracite dust; so that nearly all of the potash must be present 
in the clay. The soda probably came, it is said, from salt in the 
added sand, derived from the sea. Ordinary clay when pure is 

* On this subject see the American Journal of Science, vol. xxv, p. 440, 1883, 
and xxvii, p. 113, 1884. 



Walks and Drives about New Haven. Ill 

derived from feldspar by the removal of all its 12 per cent, or 
more of alkali, and the introduction of water. Hence the 
North Haven clay must contain much undecomposed feldspar. 
The clay and ground feldspar of the clay-beds probably corre- 
spond in origin and fineness to the impalpable earth which causes 
the milky appearance of the waters flowing from beneath a 
modern glacier. The grinding of the stones in a glacier is a 
consequence of the change of position which goes on throughout 
it as it moves. The crystalline rocks from New Haven north- 
ward contain feldspar, and hence there was an abundant supply 
close at hand for the glacier. 



34. To Stony Creek and the Thimbles. 

Stony Creek is situated on the Sound to the east of New 
Haven, 11 miles distant by road, and half an hour by the Shore 
Line cars ; and the " Thimbles " are small islands of light-colored 
gneiss and granite just off the shores. A steamer plies twice a 
day between New Haven and the islands. 

On the map of the U. S. Coast and Geodetic Survey, of which 
a copy is here introduced, the archipelago contains nearly 100 
islands, if all the bare rocks are counted ; yet the largest is 
hardly three-fourths of a mile long. In a sail through the group 
new islands are seen in quick succession — all of them white rocks 
below, but the larger green above and mostly adorned with 
groups or groves of native trees. Even the bare rocks are often 
well shaded. Pines forty feet high and other trees as large rise 
out of crevices in the rocky pavement. Besides Pines (Pinus 
rigida), the groves or forests include Oaks ( Quercus alba), a few 
sugar maples, Sassafras and Cedars ; and among the shrubs are 
the Witch-hazel, Sumach, Juniper, Bayberry (Myrica cerifera). 
On several islands the summer residence of the proprietor, or a 
cluster of them, adds to the picturesque features of the scenery, 
although as yet no great amount of money has been expended in 
architecture. On Money Island and Pot Island there are hotels. 
Prof. Verrill is possessor of the " Outer Thimble," and has there 
a delightful summer home. The islands afford no long beaches 
to bring into line and heighten incoming waves, but, instead, 



112 



II 'nil,'* and Drives about New Haven. 













-X ]■ 



<* *■ . «.&' . -jmrn 



-m imm^d 



mm?- 





i--' » Potato U « .' ■ §1* . ' 

«^T "V "" - - ji„: . i-^, 1 **^ « ' --"Hon.! 

^ov^riioTs y^-.^> « M ■ < '^'\ , '^,, , ;:) , f»i'y'. : .'.] 



•■ate - h ly^SsK, f *' >, Cjyr- i >^ i "r' < "«- ""* 




STONY CREEK 
THIMBLES. 



Walks and Drives about New Haven. 113 

bold fronts or slopes of square cut rocks, with also recesses, deep 
crevices, and long channels to receive and turn back the waters, 
quietly or thunderingly, according to the occasion ; and at low tide 
many limpid pools and basins invite attention from their various 
sea-pi-oductions. The islands have also their great glacier-brought 
bowlders ; their pot-holes of river origin, although they are 
sea-girt lands ; shell heaps of the old Indian ; and remarkable 
examples of rock degradation now in progress without aid from 
streams. The islands are among the many regions reputed to 
have been places of deposit for the buried treasures of Captain 
Kidd, and Money Island has been eagerly dug over in search of 
them. 

On leaving the cars, first take a short walk along the railroad 
cut east of the Station. It affords some idea of the kinds of 
granite and gneiss which constitute the Thimbles. The rock is 
granite to the eastward, but at the western end a very micaceous 
gneiss is intercalated. Besides this, the surface north of the cut 
is one continuous glacier-record in gi-ooves, broad channels, and 
smooth planings, telling of the abrading power of the glacier and 
the direction there of its movement — about S. 10° E. In view of 
the fact that such markings are found in all directions about 
New Haven, it may be inferred that the moving glacier did not 
slide over the gravel beneath it, but had the loose material in its 
icy grasp and made it work. This place was stripped of soil 
when the railroad was in construction about forty years since — 
the first train passing over the tracks to Saybrook July 1, 1852. 

On the way to the boat-landing, an old granite quarry is passed 
on the west side of the road at q, but out of sight as it is over 
the hill. And here a bed of mica schist occurs to the south of 
the granite and appears to dip beneath the latter. The shores 
have other outcrops of gneiss with some of mica schist ; and 
remarkable granite veins in these rocks with the red feldspar in 
large crystallizations are displayed along French Point, just 
beyond the boat wharf. 

The route among the islands should include at least Money 
Island, remarkable for the results of degradation along its shores; 
Pot Island, which has Kidd's " punch-bowl " — a pot-hole — on 
its eastern shore, besides other examples of degradation ; and 
Little Curtis Island, which is remarkable for its deep circular 



114 Walks and Drivss about New Haven. 

pot-holes. Finally, in order to understand the variations in the 
granite and gneiss, the large Beattie, or LeeWs Island, quarry, 
along Hoadly Point, should be included in the excursion. The 
finest granite is that of the Norcross & Redpath quarries, l£ 
miles north of the R. R. Station. 

The rock of the islands is mostly a feebly banded gneiss. Its 
planes of bedding or foliation — or those of the scales of black- 
mica — are often in short zigzags, giving the rock much beauty. 
Here and there very micaceous beds intervene, but only locally. 
The dip of the beds is 20° to 40° westward. 

A feature of the rocky basement of the islands observed from 
the boat in all directions is its nearly vertical fracture-planes or 
joints in parallel courses. The prevailing directions are N. 
55°-60° W. and X. 30°-35° E. Many of the long joints are 
opened a foot, and some of the capes or points are divided by 
them into sections. High Island has a long vertical cliff, 25 feet 
high, which is due to a joint. 

Landing on Money Island, the joints appear at every turn. 
Some of them are sufficiently opened to let the sea enter and ply 
its vocation of battering and loosening ; and others, as already 
stated, have trees growing from them to carry on their destruct- 
ive work of rending. In these two ways the coast of Money 
Island has become a succession of scenes of huge displaced 
blocks, and also of deep narrow water channels. 

These displacements by the sea are often promoted by the 
micaceous layers in the gneiss, and the pieces- of mica-schist 
occurring here and there which exist in the gneiss. A good 
example of the effect of much mica is seen close by the boat- 
landing on the west side of Pot Island, a little north of the 
steamboat wharf. The rock here has the usual westward dip. 
Only a few yards above the water, at a break in the rock, a very 
micaceous layer may be seen and traced downward, and the 
effects of its weakness observed. It is weak because water is 
absorbed easily along such layers ; because the black mica 
oxidizes easily ; and because the waves readily dislodge the 
scales of mica. On the east side of Money Island, east of the 
hotel, a micaceous layer intervenes between the more compact 
gneiss, with a similar display of its effects in hastening degra- 
dation. 



Walks and Drives about New Haven. 115 

Another kind of destruction observed on Money Island and 
elsewhere consists in the peeling off of thin plates from the 
exterior of the hard rock. The thin plates thus separated are 
sometimes several square feet in area and a fourth to three- 
fourths of an inch in thickness. This " desquamation " occurs 
without any appearance of decay in the rock. It is attributed to 
the expansion and contraction attending the changing tempera- 
tures of the day and night, or sunlight and shade ; and it may 
be aided by the cooling dash of the waves of the returning tide 
after the heat of a day. Freezing of water in the crevices of 
the rocks must also have its rending or displacing effects, through 
the expansion attending the process ; but probably only in the 
smaller crevices. 

Decay of the gneiss through the oxidation of the iron in the 
mica, like that at the Light House (p. 89), is also illustrated to a 
marvelous extent. •< On Pot Island, over the lower area in front 
of the hotel, toward the western shore, several of the large blocks 
of gneiss have been broken across. Outside they looked like 
solid white granite, and the best of building stone. But inside 
they are rusted to a depth of a foot or more. The mica has 
disappeared ; the feldspar and quartz are left rust-stained, but 
otherwise unaltered. The exterior of the deeply rusted masses 
derived its deceptive whiteness from a washing by the rains, 
aided perhaps by the presence in the waters of organic and 
carbonic acids. The bleaching extends to a depth of an inch. 

This work of the rusting mica is well exhibited in the cut by 
the Stony Creek Railroad Station. Ten years ago, along the 
sides of the fissures in the granite the rust had become extended 
inward 6 or 8 inches, and an interior portion remained un- 
changed. Now through the whole length of the cut the surface 
of the granite is rusted. This rusting of the surface has been 
completed in 40 years. Fissures generally carry moisture at all 
times and hence the oxidizing process is rapid along them. But 
outside surfaces dry after being rained on, and hence the oxida- 
tion over them is slow. The weakness is due to the rock's being 
porous ; so far as it takes in water, it rusts. Pyrite adds but 
little to the result. 

The veins of granite in the region have considerable interest. 
They usually consist of red feldspar in large crystallizations 
with quartz and some mica, and rarely a little magnetite. 



116 Walks and Drives about New Haven. 

The gneiss of the islands has many such veins. At Beattie's 
quarry a large granite vein, near the middle of -its western half, 
affords small pale green crystals of the mineral apatite (calcium 
phosphate). Apatite looks like beryl, but a touch with the point 
of a knife-blade will prove it to be too soft for that species. The 
crystals are small, seldom over a fourth of an inch thick. The 
best have been obtained from the debris about the vein ; they 
had fallen out of the rock in the quarrying. The black mica 
(biotite) of the vein, which is in large crystals, decomposes so 
readily that the most of it will be found to have lost its lustre. 

Veins are fillings of fissures from below or from either side by 
infiltration of solutions or vapors at a slow rate ; very slow and 
prolonged to produce so coarse crystallizations of red feldspar as 
here occur. The rocks were variously shoved about as well as 
broken to make fissures for veins having the great irregularities 
observed on French Point. 

Besides granite veins, quartz veins may be met with. They 
intersect those of granite when they occur together, and thus 
show that the latter were formed first. This order of succession 
in the veins accords with the fact that depositions of feldspar 
and mica form only at high temperatures, and those of quartz 
may be made at low, and therefore during the later stages of an 
epoch of metamorphic change and vein-making. 

The pot-hole on Pot Island, called Kidd's Punchbowl, is on 
the rocky northeast shore, above the level of tides and waves. 
It is shaped like a bread-tray, being 2X4 feet broad and a foot 
and a half deep. It is hence a poor example of a pot-hole, and 
would hardly be called one were not its inner surface so well 
smoothed. The rocking of a large stone over the spot by the 
dash of the waves or the rush of a torrent may have made it. 
But if the work of the waves, or a torrent, the water-level was 
different from the present : — higher to give the waves a chance; 
but much lower to afford a land area for a river. 

Little Curtis Island is well worth visiting for its two pot-holes 
on its eastern shore. These are deep cylindrical borings into the 
hard rock. The larger is 74- feet deep and 3 in diameter ; and 
among the rounded stones taken out of it was one a foot in 
diameter. One of trap, is 16x8x8 inches in its dimensions. 
The other pot-hole is 10 inches across and was originally, as 
traces of its upper part show, about 3 feet deep. It is situated 



Walks and Drives about New Haven. 117 

a little to the north of the other. Such vertical borings into 
a granite-like rock imply the long-continued revolution of a ver- 
tically-acting abrader. Waves cannot thus act. Neither could 
a cascade through the crevasse of a glacier, however well sup- 
plied with stones; for a glacier keeps moving, instead of stopping 
to make a vertical 7-foot bore into granite. Rapid streams 
along their rocky shores — making concentric whirls of stones 
owing to the form of the bottom and its position with reference 
to the current — are the only agency. Hence when the granite 
of Little Curtis Island was being bored, the present sea-bottom 
was above the sea-level. The map shows that the stream now 
flowing west of Hoadly Point was the probable agent. The 
time may have been the Glacial period. The above facts and 
others make it probable that during this period the land along 
southern Connecticut stood 100 to 150 feet above its present 
level. 

Little Curtis Island has large Indian shell-heaps. The shells 
are mainly of oysters, and many are 10 inches long and narrow. 
There are a few of the round-clam, and none of the long-clam. 
Like others of the group, these shell-heaps have not yet afforded 
any arrow-heads or other implements, but they may to future 
searchers. The sea-border Indians, with food plenty in the 
waters, had little use for hunting apparatus. Moreover there is 
no evidence that the Indians cooked their oysters. 

A walk through the extensive Beattie quarry is instructive. 
There are wide variations in the gneiss from the most strongly 
banded (in a cross-section), owing to the abundance of black 
mica in large scales, to the feebly banded ; and the latter shades 
off into granite. The granite of the Stony Creek region con- 
tains usually two feldspars : a flesh-red, which is orthoclase or 
potash-feldspar, and a white, which is albite or soda-feldspar; 
and also two micas : the light-colored muscovite, containing 
little or no iron or magnesia, and the black biotite, containing 
both iron and magnesia. But mica of either kind is very 
sparingly present, and muscovite the least so. This gradation of 
gneiss into granite is attended therefore with a large diminution 
in the amount of mica. 

The association of the two rocks and their frequent transitions 
show that they were formed under similar conditions. At the 



118 Walks and Drives about New Haven. 

same time, the large amount of iron and magnesia in one, and 
the very small in the other, is proof that the gneiss could not 
have been made from the granite, although a gneissoid structure 
may be produced in the latter by pressure. Further black mica 
schist (more or less hornblendic) alternates in some places with 
the gneiss and hence is a third kind of rock in the series — and a 
kind as much underivable in any way from granite as granite is 
underivable from a black mica-schist. 

The rocks are examples of the metamorphic rocks of geology, 
that is, rocks that have been changed or metamorphosed from 
the condition of common uncrystalline strata into crystalline. 
The delicate wavy lines or zigzags in the planes of bedding or 
foliation in much of the gneiss of the islands is evidence that 
under the pressure to which the beds were subjected the rocks 
were more or less softened in some parts by the heat and vapor; 
and the fragments of mica-schist, from the size of the hand to 
those that are rods in length, found in the rocks, indicate thai 
they were much broken, faulted and mended during the progress 
of the crystallization. 

The decay of granite and gneiss in the region gives a hint as 
to the origin of the sands of the Red sandstone. The results of 
this decay are granitic sands, with only the black mica wanting, 
and the quartz and feldspar have very nearly the proportions in 
granite. Moreover they are colored or stained with iron oxide. 
These are precisely the materials needed to make the sandstone. 
The sands, therefore, were simply gathered from the land by 
streams and hurriedly transferred to the Connecticut valley 
estuary. Had the feldspar in the decay of the rocks been 
changed to clay (as is often done by the action of carbonic acid) 
there would have been clayey beds among the sand-beds ; but 
these are absent from the New Haven region and are mostly so 
elsewhere. Had the waves of a seashore helped in their dis- 
tribution, the feldspar would have been ground up and drifted 
off, and the sandstones would have been made mainly or wholly 
of quartz sands. 

This explanation of the origin of the sandstone fails in only 
one point: the rock is colored with the red oxide of iron (Fe 2 O a ), 
not with the brownish yellow oxide (Fe 2 0. ( -f water). To this it 
may be urged that the oxide produced in the region in Triassic 



Walks and Drives about New Haven. 119 

time by the oxidation may have been the red oxide, as it is now 
in some warm regions. If this was so, the explanation is com- 
plete. But if it is not admitted, there is the fact that the yellow 
oxide when heated to 212° F. in boiling water or otherwise, 
becomes the red, as it does in making brick. Consequently, heat 
coming up through fissures in the epoch of the trap eruptions 
and diffused through the waters of the Connecticut valley estu- 
ary, supposing the sandstone still submerged, might have made 
the rusty beds red. This result is not incredible in such a 
region, at a time when it was having eruptions of melted rock 
through enormous fissures along its whole length, and when heat 
and vapor must have been escaping also from multitudes of 
smaller fissures. 

On the return by the cars to New Haven, it may be noticed, 
soon after leaving the station, that there are many low isolated 
hills of granite-like rock on either side of the railroad, and that 
a slight sinking of the land would extend the archipelago of 
the present waters. 



35. To the Peabody Museum. 

The Peabody Museum of Yale College is open between the 
hours of 9 and 6 in summer and 9 and 5 in winter. All rooms 
that are accessible to visitors have their doors wide open. On 
the first floor is the collection of minerals and meteorites; on the 
second, that of fossils ; on the third, are the zoological collec- 
tions ; on the fourth, the archaeological collections. 

On the second floor, in the central part of each room, there are 
large slabs of red sandstone from the Jura-Trias formation of the 
Connecticut valley, which are covered with footprints of some of 
the biped Reptiles (or Reptiles and Birds) that then populated 
the Connecticut valley ; and if the valley, probably also much of 
the continent. The animals that made them are for the most 
part referred to the tribe of Dinosaurs by Marsh. One long slab 
between the cases in the western room is covered with rain-drop 
impressions ; and, in addition, it is crossed by two lines of tracks 
— one of them of a largish animal that slumped in at each tread, 
and the other of a small one that left well-defined tracks ; and it 



120 Walks and Drives about New Haven. 

may be learned from the slab, by means of the rain-drop impres- 
sions, whether the walk of the latter was byfore or after the 
rain. Moreover, as the position of the slab is known, it bears a 
record, in the oblong form of the rain-drop impressions, of the 
direction of, the wind at the time. 

Other smaller specimens of tracks are contained in cases num- 
bered 37 and 38, and some of them show impressions of both the 
fore and hind feet. The portions of skeletons discovered in the 
sandstone are not yet in the cases. Some of the slabs are from 
the Portland quarries, near Middletown, and many from Turner's 
Falls near Greenfield, Mass. The New Haven sandstone has not 
afforded any tracks because most of the rock which is quarried 
here is too coarse to have received such impressions. 

There are no specimens of the same sjjecies yet known from 
other parts of the continent outside of the Jura-Trias formation. 
The bones of some related Dinosaurs from Jurassic beds in the 
Rocky Mountain region, later in time than those of the Jura- 
Trias, are to be seen in the western room. Those of one species 
— Brontosaurus of Marsh — are lying on the floor. Those of 
another — Stegosaurus of Marsh — are contained in the upright 
cases numbered 17, 18, against the northern wall ; and in the 
first horizontal case on the right, there are the huge plates and 
spines with which the middle of its back and tail were armed. 
But these species of Dinosaurs, unlike those of the Connecticut 
valley, walked on all fours. The large upright specimen of a 
Reptile in the center of the room, facing the door, is not 
Jurassic but belongs to the following Cretaceous or Chalk period, 
which is not represented in the New Haven region. The species 
i- :i Mososaur, of the Genus Holosaurus of Marsh, and is from 
Kansas. To the same Cretaceous period belong the specimens of 
a large Kansas bird, which had teeth like a reptile and is named 
Hesperornis by Marsh, in the first horizontal case to the left of 
the door. 

In the third story, western room, the cases 52-58 inclusive, 
contain a very full collection of specimens, made by Prof. Verrill 
of the marine life of the New England coast and the deeper 
waters outside. All are labelled with names and localities. 

These few directions will help those interested to profit by the 
study of the other labelled specimens in the Museum collections. 



Plate 




MAP OF THE NEW HAVEN REGION. 

Scale -j 4 (j inch = l mile, or 1 inch = 2^ miles. 
Explanations. — A, Alliugtown ; B, Beacon Hill; Bh, Beaver Hills; E, East 
Rock ; Ed, Edgewood ; F, Fort Hale ; F", Ferry Point, or Red Rock, on the Quin- 
nipiac; L, Old Light House; M. Mill Rock; M P, Maltby Park; P, Pine Rock; 
Rd, Round Hill; Rt, Rabbitt or Peter's Ruck: Sin, Sachem's Ridge; T, Tomlin- 
son's bridge, across the head of New Haven Bay; W, West Rock ; Wn, Warner's 
Rock: W L. "vv'intergreen Lake: bm, Beaver Pond Meadows; /(below WL) Win- 
tergreen Falls; nl, w2, re3, w4, different notches in the West Rock ridge; nA, the 
Wintergreen Notch. 



PLATE U 




v 




PLA.TR VI. 




< 

8' 

9 a 

B ft 







^ 



